Exploring Prehistoric Life

Crepidosoma doyleii: This New Species of Brittle Star Lived 435 Million Years Ago

Monday, January 22, 2018

Scientists say the fossilized remains of a brittle star that lived 435 million years ago belong to a new species. 

The fossil was named Crepidosoma doyleii, after the paleontologist who discovered it. Eamon Doyle was a Ph.D. student when he discovered the remains of the thumbnail-sized creature in the late 1980s, embedded in a layer of fossils on a hillside in the Maam Valley in Ireland. 

Though this species of brittle star (which are closely related to starfish) first developed nearly half a billion years ago, its modern day descendants are remarkably similar.

This particular species was a marine scavenger and lived through continental shifts, oceans rising and draining, and the extinction of the dinosaurs. The brittle star that Doyle found most likely lived in the ocean over what's now Ireland, which disappeared after tectonic plate shifts. 

Researchers published their findings on Crepidosoma doyleii this month in the Irish Journal of Earth Sciences

According to Doyle, this brittle star is incredibly resilient — it was around during the Silurian period, when the first land plants evolved. 

The discovery is significant because it's a "key piece of evidence in the hunt for past life in the ocean that covered Ireland," David Harper, a paleontologist at Durham University and co-author of the study, told the Irish Times

The fossil will be put on display at the National Museum of Ireland.


Source: mashable.com

U of A Digitally Preserves Important Dinosaur Tracks Found in Arkansas

Thursday, January 18, 2018

Scientists using laser-imaging technology have documented and digitally preserved the first known set of theropod dinosaur tracks in the state of Arkansas.

The tracks, discovered in 2011 in a working gypsum quarry near Nashville, have since been destroyed. But high-resolution digital scans taken over a period of two weeks in 2011 allowed a team of researchers to study the tracks and determine that they were made by Acrocanthosaurus, a large, carnivorous dinosaur. The findings extended the known range of Acrocanthosaurus 56 miles east, to the western shore of an ancient inland sea.

“It actually confirms that the main genus of large theropods in North America was Acrocanthosaurus,” said Celina Suarez, an assistant professor in the Department of Geosciences who was part of the team that documented and studied the tracks. “It now has been found in Wyoming, Utah, Oklahoma, Arkansas and Maryland, a huge range.”

Results of the study were recently published in the journal PLOS ONE. Researchers also created a detailed, publicly accessible online map of the site and the tracks. Brian Platt, an assistant professor of geology from the University of Mississippi, led the study. Researchers from the University of Arkansas Center for Advanced Spatial Technology (CAST) provided the scanning equipment and expertise.


After the tracks were discovered, researchers received a $10,000 Rapid Grant from the National Science Foundation to quickly document the site. The U of A’s vice provost for research and economic development and the J. William Fulbright College of Arts and Sciences provided matching grants, for a total of $30,000.

The mining company moved its operations to allow researchers a short window of time to document the find. Researchers used LiDAR, which stands for light detection and ranging, because traditional methods would have taken too long, said Suarez. “From a technical standpoint, it’s important that the ability to rapidly scan such a large area is available to paleontologists. It was invaluable for this project since we had such little time to work.”

The site had two different sized Acrocanthosaurus tracks, suggesting both adult and younger animals walked the ancient tidal flat about 100 million years ago, during the Cretaceous Period. It also contained tracks made by sauropods, long-necked plant-eating dinosaurs.

LiDAR uses a pulsed laser to measure distances to the earth in tiny increments, generating a data “point cloud” that is used to digitally recreate a physical space. In this case, the equipment was mounted on a lift over the site. By analyzing carbon and oxygen isotopes of the rock at the track surface, researchers determined that the track surface was indeed the surface that the animals stepped on, rather than an underlying layer that remained when the original surface eroded.

The digital reconstruction of the trackway site can be viewed at the CAST website.

About the University of Arkansas: The University of Arkansas provides an internationally competitive education for undergraduate and graduate students in more than 200 academic programs. The university contributes new knowledge, economic development, basic and applied research, and creative activity while also providing service to academic and professional disciplines. The Carnegie Foundation classifies the University of Arkansas among only 2 percent of universities in America that have the highest level of research activity. U.S. News & World Report ranks the University of Arkansas among its top American public research universities. Founded in 1871, the University of Arkansas comprises 10 colleges and schools and maintains a low student-to-faculty ratio that promotes personal attention and close mentoring.

Source: https://news.uark.edu

The Fossil Record of Evolution - Descent with Modification - Lists of Transitional Fossils & Transitional Forms

Tuesday, January 23, 2018

Transitional Fossils – Evidence of Evolution

What is a Transitional Fossil?

A transitional fossil is a fossil of an organism that has traits from multiple evolutionary stages. Proponents of creationism claim that “evolutionists have had over 140 years to find a transitional fossil and nothing approaching a conclusive transitionalform has ever been found”, despite the discovery of Archaeopteryx (a transitional form between maniraptoran dinosaurs and basal (primitive) birds, and among the best examples of evolution) only two years after Darwin published The Origin of Species. Creationists say that we never saw evolution happen, but transitional fossils are the next best thing.

What are Transitional Forms?

“A transitional form is an organism that has features intermediate of its ancestors and progeny. The term is most common in evolution to refer to organisms that show certain features (wings, feathers, gills and so on) partly in development. In theory, every fossil is a transitional form if it has descendants and each living creature is a transition between its parent and its offspring. However, evolution is about the features of populations rather than individuals; the transition at the species level can be too small in fossils; so the list below concentrates on broad transitional features and the genus or larger group.”

Transitions in vertebrates before the Cenozoic

Invertebrate to Vertebrate

  • Unnamed Upper (U.) Pre-Cambrian chordate — First to bear a primitive notochord; archaetypical chordate.
  • Pikaia gracilens — Middle (M.) Cambrian chordate with lancelet-like morphology.
  • Haikouella — Lower (L.) Cambrian chordate, first to bear a skull; archaetypical craniate.
  • Haikouichthys — L. Cambrian quasi-vertebrate, intermediate in developing a vertebral column; archaetypical vertebrate.
  • Conodonts — U. Cambrian to Triassic quasi-vertebrates with spinal cord; "bug-eyed lampreys".
  • Myllokunmingia — L. Cambrian vertebrate with primitive spinal column; oldest true crown-group vertebrate.
  • Arandaspis — L. Ordovician vertebrate, armoured jawless fish (ostracoderm), oldest known vertebrate with hard parts known from (mostly) complete fossils.

Jawless Fish to Jawed Vertebrate

  • Birkenia — Silurian primitive, jawless fish, a typical member of the Anaspida
  • Cephalaspis — Silurian armoured jawless fish, archaetypical member of the "Osteostraca," sister group to all jawed vertebrates.
  • ShuyuSilurian to Devonian, armoured jawless fish belonging to Galeaspida, related to Osteostraca. Internal cranial anatomy very similar to the anatomy seen in basal jawed vertebrates. This similarity is directly implied with the translation of its name, "Dawn Fish," with the implication that it represents the "dawn of jawed vertebrates."

Acanthodian to shark

  • Ptomacanthus — sharklike fish, originally described as an acanthodian fish: brain anatomy demonstrates that it is an intermediate between acanthodians and sharks.
  • Cladoselache — primitive/basal shark.
  • Tristychius — another sharklike fish.
  • Ctenacanthus — primitive/basal shark.
  • Paleospinax — sharklike jaw, primitive teeth.
  • Spathobatis — Ray-like fish.
  • Protospinax — Ancestral to both sharks and skates.

Primitive jawed fish to bony fish

  • Acanthodians — superficially similar to early bony fishes, and some have been identified as being the ancestors of sharks.
  • Palaeoniscoids — primitive bony fishes.
  • Canobius, Aeduella — palaeoniscoids with more advanced jaws.
  • Parasemionotus — combination of modern cheeks with more primitive features, like lungs
  • Oreochima — first teleost fish
  • Leptolepids — vaguely herring-like ancestors of modern teleost fish. Lung modified into swim bladder.
  • Amphistium and Heteronectes — percomorphs that demonstrate the transition of the eye location of flatfishes.

Fish to amphibian

  • Paleoniscoids — both ancestral to modern fish and land vertebrates
  • Osteolepis — modified limb bones, amphibian like skull and teeth
  • Kenichthys — shows the position of exhaling nostrils moving from front to fish to throat in tetrapods in its halfway point, in the teeth
  • Eusthenopteron, Sterropterygion — fin bones similarly structured to amphibian feet, but no toes yet, and still fishlike bodily proportions
  • Panderichthys, Elpistostege — tetrapod-like bodily proportions.
  • Obruchevichthys — fragmented skeleton with intermediate characteristics, possible first tetrapod.
  • Tiktaalik — a fish with developing legs. Also appearance of ribs and neck.
  • Acanthostega gunnari—famous intermediate fossil. most primitive fossil that is known to be a tetrapod or four legged animal from the Upper Devonian of Greenland, which has shed significant light on the derivation and early evolution of tetrapods. It had legs and feet but was aquatic, not an amphibian.
  • Ichthyostega — like Acanthostega, another fishlike amphibian
  • Hynerpeton — A little more advanced then Acanthostega and Ichtyostega
  • Labyrinthodonts — still many fishlike features, but tailfins have disappeared
  • Gars — Fish with vascularized swim bladders that can function as lungs
  • Lungfish and Birchirs — fish that have lungs

Primitive to modern amphibians

  • Temnospondyls
  • Dendrerpeton acadianum
  • Archegosaurus decheni
  • Eryops megacephalus
  • Trematops
  • Amphibamus lyelli
  • Doleserpeton annectens
  • Triadobatrachus — a primitive frog.
  • Vieraella — an early modern frog
  • Karaurus — a primitive salamander

Amphibian to reptile

  • Proterogyrinus
  • Limnoscelis
  • Tseajaia
  • Solenodonsaurus
  • Hylonomus
  • Paleothyris

Early reptile to diapsid

  • Hylonomus
  • Paleothyris
  • Petrolacosaurus
  • Araeoscelis
  • Apsisaurus
  • Claudiosaurus
  • Planocephalosaurus
  • Protorosaurus
  • Prolacerta
  • Proterosuchus
  • Hyperodapedon
  • Trilophosaurus

Early diapsid to turtle

  • Pappochelys rosinae — diapsid skull with expanded ribs and fused gastralia
  • Odontochelys semitestacea — secondary loss of temporal fenestrae, partial formation of a turtle shell, showing how the hard underbelly, or plastron, formed first.
  • Deltavjatia vjatkensis
  • Proganochelys

Early synapsid to mammal

  • Paleothyris
  • Protoclepsydrops haplous
  • Clepsydrops
  • Archaeothyris
  • Varanops
  • Haptodus
  • Dimetrodon
  • Sphenacodon
  • Biarmosuchia
  • Procynosuchus
  • Dvinia
  • Thrinaxodon
  • Cynognathus
  • Diademodon
  • Probelesodon
  • Probainognathus
  • Exaeretodon
  • Oligokyphus
  • Kayentatherium
  • Pachygenelus
  • Diarthrognathus
  • Adelobasileus cromptoni
  • Sinoconodon
  • Kuehneotherium
  • Eozostrodon
  • Morganucodon -- a transition between "proto mammals" and "true mammals".
  • Haldanodon
  • Peramus
  • Endotherium
  • Kielantherium
  • Aegialodon
  • Steropodon galmani
  • Vincelestes neuquenianus
  • Pariadens kirklandi
  • Kennalestes
  • Asioryctes
  • Procerberus
  • Gypsonictops
  • Juramaia
  • Eomaia
  • Sinodelphys

Dinosaur to bird

  • Kulindadromeus — A basal neornithischian (Ya know, Triceratops, Iguanodon, Hypsilophodon, and such) with feathers.
  • Allosaurus — A large theropod with a wishbone.
  • Aerosteon — A large theropod of the same lineage as the aforementioned Allosaurus that was discovered to have air sacs supplementing lungs, like modern birds.
  • Compsognathus — A small coeleurosaur with a wishbone.
  • Epidendrosaurus
  • Epidexipteryx
  • Scandoriopteryx
  • Gigantoraptor — A large oviraptorosaur discovered brooding its nests in order to protect and incubate eggs.
  • Gobivenator
  • Mei — A troodont discovered sleeping with its head underneath its wing/
  • Saurornithoides
  • Sinovenator
  • Buitreraptor
  • Pyroraptor
  • Unenlagia
  • Graciliraptor
  • Bambiraptor
  • Balaur — A large flightless bird.
  • Tsaagan
  • Dromaeosaurus
  • Sinosauropteryx — a basal coelurosaur discovered to be covered in feathers. It is also the first dinosaur to have its colour determined, thanks to preserved pigment structures in the feathers.
  • Protarchaeopteryx
  • Caudipteryx
  • Velociraptor — a very famous dromaeosaur discovered to have quill knobs on it's wrists. For SOME odd reason, sadly. everyone sees these things as mutant allosaur-looking... uh... things.
  • Deinonychus
  • Utahraptor
  • Achillobator
  • Oviraptor — the first dinosaur discovered to steal brood nests.
  • Sinovenator
  • Beipiaosaurus
  • Lisboasaurus
  • Sinornithosaurus
  • Microraptor — a feathered bird with distinctly dinosaurian characteristics, such as its tail.
  • Xiaotingia — slightly earlier than Archaeopteryx, slightly more like a dinosaur and less like a bird
  • Archaeopteryx — the famous bird-with-teeth.
  • Anchiornis
  • Baptornis
  • Rahonavis
  • Confuciusornis
  • Sinornis
  • Iberomesornis
  • Therizinosaurus
  • Nothronychus
  • Citipati
  • Falcarius
  • Alxasaurus
  • Chirostenotes
  • Avimimus
  • Khaan
  • Incisivosaurus
  • Caenagnathus
  • Troodon
  • Byronosaurus
  • Ingenia
  • Hesperonychus
  • Conchoraptor
  • Patagopteryx
  • Ambiortus
  • Hesperornis — A diving seabird with prominent teeth. It's also completely flightless.
  • Apsaravis
  • Ichthyornis — A flying seabird with prominent teeth.
  • Columba — One of many typical modern birds.

Transitional mammalian fossils


  • Purgatorius — the earliest primate-like organism
  • Plesiadapis — Mammal closely related to primates.
  • Carpolestes — Mammal closely related to primates
  • Archicebus — First euprimate, or something very similar to it.
  • Omomys — Tarsier-like primate
  • Eosimias — Basal anthropoid
  • Amphipithecus — Another basal anthropoid
  • Apidium — The first, primitive monkey.
  • Propliopithecus — Primitive New World Monkey
  • Darwinius masillae — a link between earlier primates and later ones.
  • Dryopithecus Primitive ape.
  • Proconsul Primate that is closely related to apes.
  • Sivapithecus Primate closely related to the ancestors of Orangutans
  • Djebelemur First lemuriform primate.
  • Cantius Extremely primitive prosimian from the Early Eocene of North America.
  • Teilhardina First North American primate.

Non-human primate to human

  • Sahelanthropus — possible candidate for last human-chimpanzee common ancestor; from placement of skull possibly walked upright.
  • Orrorin — possible human ancestor, may have walked upright as shown by shape of femur.
  • Ardipithecus
  • Australopithecus — a genus of bipedal apes
    • Australopithecus sediba — advanced Australopithecus showing more human features
  • Homo habilis — a transitional form from Australopithecus to later Homo
  • Homo rudolfensis — a type of Homo habilis or a different species
  • Homo ergaster — a form of Homo erectus or a distinct species
  • Homo erectus — a transitional form from Australopithecus to later Homo (Latin for "human") species
  • Homo heidelbergensis — a possible common ancestor of modern man and Homo neanderthalensis
  • Homo neanderthalensis — Neanderthals likely interbred with modern humans.
  • Homo sapiens idaltu archaic subspecies of modern human, possibly ancestral to Homo sapiens sapiens (modern humans).


  • Indohyus — a vaguely chevrotain-like or raccoon-like aquatic artiodactyl ungulate with an inner ear identical to that of whales.
  • Ambulocetus— an early whale that looks like a mammalian version of a crocodile
  • Pakicetus — an early, semi-aquatic whale, a superficially wolf-like animal believed to be a direct ancestor of modern whales.
  • Rhodocetus — An early whale with comparatively large hindlegs: not only represents a transition between semi-aquatic whales, like Ambulocetus, and obligately aquatic whales, like Basilosaurus.
  • Basilosaurus — A large, elongated whale with vestigial hind flippers: transition from early marine whales (like Rhodocetus) to modern whales
  • Dorudon — A small whale with vestigial hind flippers, close relative of Basilosaurus.

    READ MORE: Whale Evolution


  • Eritherium
  • Phosphatherium
  • Numidotherium
  • Barytherium
  • Phiomia
  • Prodeinotherium
  • Stegodon

Transitional plant fossils

  • Cooksonia — early vascular plant
  • Archaeopteris — early tree
  • Williamsonia — an early flowering plant ("stem angiosperm")

Transitional Fossils & Transitional Forms

Misconception: “Gaps in the fossil record disprove evolution.”

Response: The fact that some transitional fossils are not preserved does not disprove evolution. Evolutionary biologists do not expect that all transitional forms will be found and realize that many species leave no fossils at all. Lots of organisms don’t fossilize well and the environmental conditions for forming good fossils are not that common. So, science actually predicts that for many evolutionary changes there will be gaps in the record.

READ ALSO: 10 Common Myths About Evolution

Also, scientists have found many transitional fossils. For example, there are fossils of transitional organisms between modern birds and their theropod dinosaur ancestors, and between whales and their terrestrial mammal ancestors.

Source: Wikipedia.com, NatGeo.com

STUDY: Sharks, humans shared common ancestor 440 million years ago

Sunday, January 14, 2018

Acanthodes bronni

"These different experiments in shark-like conditions give a picture of inevitability of the evolution of modern sharks," researcher Michael Coates said.

A basking shark-like fish -- only the size of a sardine -- is helping paleontologists better understand the earliest branches of the vertebrate family tree. The fish's 385 million-year-old remains suggest sharks and humans shared a common ancestor 440 million years ago.

The shark, named Gladbachus adentatus, was first discovered in Germany in 2001. But it wasn't until recently that, with the help of modern technology, scientists began to understand what they were looking at.

The specimen was found flattened and preserved in resin. The shark's exoskeleton, including its cranium, cartilage and gill details, were all neatly preserved, but its compressed state made it difficult to decipher what exactly the shark looked like.

Improved CT scanning technologies helped researchers recreate the shark in 3D.

3-D reconstruction of the jaws, gill arches and braincase of Gladbachus adentatus.  Credit: Michael Coates and Kristen Tietjen, University of Chicago.

"Gladbachus was not your typical shark," Katharine Criswell, a zoologist and research fellow at the University of Cambridge, told UPI. "It was almost a meter long and had a large and broad head with very tiny teeth, suggesting it was a suspension feeder similar to modern basking sharks."

Criswell and her colleagues were drawn to Gladbachus because of the potential insights it offered -- insights into a period of shark evolution of which little is understood.

Gladbachus lived during the Devonian period, between 416 million to 358 million years ago.

"We know of only a handful of completely preserved early shark fossils from this time period, and Gladbachus is one of the oldest," Criswell said.

The lack of shark remains from the period has long puzzled scientists.

"Sharks are thought of as a very conservative, primitive group and one of the best available early primitive models for vertebrates as a whole," said Michael Coates, an evolutionary biologist at the University of Chicago. "But they also present a paradox."

The fossil evidence -- or lack there of -- doesn't support the conception of sharks as a slowly evolving, primitive group.

"Bony fishes goes back deep into the fossil record, as far back 420 million years," Coates said. "There is a better record of bony fishes than there is of anything shark-like."

The vertebrate lineage that began with bony fishes eventually spawned mammals, including humans. Sharks, which utilize more cartilage than bone, split off and formed a separate branch. But with few fossils of early sharks or shark-like fish, scientists have struggled to pinpoint the split.

 New analysis of the Gladbachus adentatus fossil both widens and complicates the shark family tree. Photo byJason Smith

Thanks to Gladbachus, scientists are starting to nail down the timing of early vertebrate evolution.

Even if the shark offers some clarity, evolution is never straightforward. The transition from primitive shark-like fish to advanced or specialized shark species wasn't smooth.

Coates likens early species like Gladbachus to an evolutionary experiment. Other shark-like species represent separate but similar experiments, each trying out a variety of evolutionary adaptations.

"These different experiments in shark-like conditions give a picture of inevitability of the evolution of modern sharks," Coates said.

But a species isn't just a single experiment. Each species -- each specimen, even -- is a thousand different anatomical experiments at once. Some of those experiments prove successful enough that they become standard.

By better understanding the relationship between early sharks and bony fish, scientists can trace the origins of anatomical structures shared by all vertebrates.

"The body plan of jawed vertebrates, the group that includes humans, fish with bony skeletons, and sharks, is distinguished by features like jaws, teeth, and two sets of paired fins," Criswell said. "This body plan can be traced back to the evolutionary origin of sharks and bony fishes."

By comparing the anatomical makeup of Gladbachus with data from other early shark and fish fossils, researchers showed the first jawed vertebrates emerged nearly 10 million years earlier than was previously thought. They detailed the revelation in the Proceedings of the Royal Society B: Biological Sciences.

Researchers believe remains of more shark-like and bony fish experiments are out there waiting to be discovered.

"Each one will help us calibrate the timescale of our shared evolutionary traits," Coates said.

Source: www.upi.com


Vulcanops jennyworthyae: Giant New Species of Burrowing Bat

Saturday, January 13, 2018

An artist’s impression of the New Zealand greater short-tailed, or burrowing, bat (Mystacina robusta) that went extinct last century. Vulcanops jennyworthyae is the biggest burrowing bat yet known. It also represents the first new bat genus to be added to New Zealand’s fauna in more than 150 years. Image credit: Gavin Mouldey.

Burrowing bats (family Mystacinidae) are only found now in New Zealand, but they once also lived in Australia.

They are peculiar because they not only fly; they also scurry about on all fours, over the forest floor, under leaf litter and along tree branches, while foraging for both animal and plant food.

“Burrowing bats are more closely related to bats living in South America than to others in the southwest Pacific,” said Professor Sue Hand, from the University of New South Wales in Australia.

“They are related to vampire bats, ghost-faced bats, fishing and frog-eating bats, and nectar-feeding bats, and belong to a bat superfamily that once spanned the southern landmasses of Australia, New Zealand, South America and possibly Antarctica.”

The newly found fossil bat, named Vulcanops jennyworthyae, was relatively large, with an estimated body mass of 40 g.

It fossilized remains (teeth and bones) were recovered from freshwater lake sediments (16-19 million years old) near St Bathans, Central Otago, South Island.

“New Zealand’s burrowing bats are renowned for their extremely broad diet. They eat insects and other invertebrates such as weta and spiders, which they catch on the wing or chase by foot. And they also regularly consume fruit, flowers and nectar,” Professor Hand said.

“However, Vulcanops jennyworthyae’s specialized teeth and large size suggest it had a different diet, capable of eating even more plant food as well as small vertebrates — a diet more like some of its South American cousins. We don’t see this in Australasian bats today.”

“The fossils of this spectacular bat and several others in the St Bathans Fauna show that the prehistoric aviary that was New Zealand also included a surprising diversity of furry critters alongside the birds,” said Dr. Trevor Worthy of Flinders University.

“These bats, along with land turtles and crocodiles, show that major groups of animals have been lost from New Zealand,” added Professor Paul Scofield of Canterbury Museum.

“They show that the iconic survivors of this lost fauna — the tuataras, moas, kiwi, acanthisittid wrens, and leiopelmatid frogs — evolved in a far more complex community that hitherto thought.”

This diverse fauna lived in or around a 5,600-km2 prehistoric Lake Manuherikia that once covered much of the Maniototo region of the South Island. When they lived, temperatures in New Zealand were warmer than today and semitropical to warm temperate forests and ferns edged the vast paleolake.

Vulcanops jennyworthyae provides new insight into the original diversity of bats in Australasia,” the paleontologists said.

“Its lineage became extinct sometime after the Early Miocene, as did a number of other lineages present in the St Bathans assemblage.”

“These include crocodiles, terrestrial turtles, flamingo-like palaelodids, swiftlets, several pigeon, parrot and shorebird lineages and non-flying mammals. Most of these were probably warm-adapted species.”

“After the middle Miocene, global climate change brought colder and drier conditions to New Zealand, with significant changes to vegetation and environments.”

“It is likely that this general cooling and drying trend drove overall loss in bat diversity in New Zealand, where just two bat species today comprise the entire native land mammal fauna.”

The team’s findings are published in the journal Scientific Reports.


Suzanne J. Hand et al. 2018. A new, large-bodied omnivorous bat (Noctilionoidea: Mystacinidae) reveals lost morphological and ecological diversity since the Miocene in New Zealand. Scientific Reports 8, article number: 235; doi: 10.1038/s41598-017-18403-w

Source: www.sci-news.com

13 Best Places in Britain to see Dinosaurs and Fossils

Friday, January 19, 2018

University of Manchester museum T. rex

Before humans, dinosaurs ruled the world, prowling the land, sea and air for around 165 million years. Here’s our pick of some of the best museums to see these spectacular creatures and spark your imagination, in no particular order…


New Walk Museum

© Leicester City Council

The impressive Rutland Dinosaur, a Cetiosaurus oxoniensis, takes centre stage at the New Walk’s famous Dinosaur Gallery which is also home to some of the oldest fossils in the world. Displays include the Plesiosaur, the giant fish and the 540 million-year-old Charnia fossil. There are also dinosaur interactives and cutting edge reconstructions of marine reptiles.

Dinosaur Isle
Isle of Wight

© Dinosaur Isle Museum. Photograph by Thearle

The Isle of Wight is one of the richest dinosaur locations in Europe, with more than 20 species from the Cretaceous period found on the island. The interactive Dinosaur Isle Museum has reconstructions of five local dinos; Neovenator, Eotyrannus, Iguanodon, Hypsilophodon and the giant sauropod. Displays use clever lighting, sounds, smells and animatronic technology to create an exciting and at times scary experience for visitors. They also lead very popular fossil walks throughout the year.

Lyme Regis Museum
Lyme Regis

Courtesy of Lyme Regis Museum

Housed in her former home, Lyme Regis Museum celebrates the pioneering fossil hunter and palaeontologist Mary Anning, who discovered the Ichthyosaur on the local beaches in 1811. The Geology Gallery contains a wealth of fossils and for the real thing you can join one of their famous fossil walks along a historic stretch of Dorset coast.

Manchester Museum

‘Empty’ © jev55 (CC BY-NC 2.0)

Stan the Tyrannosaurus rex is the towering centrepiece to this impressive palaeontology collection of more than 100,000 fossils. Search out the giant Plesiosaur and marvel at the massive fossil tree. The museum is home to dinosaurs, mummies and live animals and is an engaging place to visit to learn how our planet has changed over millions of years.


Natural History Museum

© The Trustees of the Natural History Museum

The terrifying animatronic T. rex and the one-of-kind Stegosaurus skeleton make the NHM a must-see museum for any dinosaur enthusiast. The museum is packed full of facts, figures, fossils, reconstructions and engaging interactives that explore an ever-developing knowledge of dinosaurs.

Dorset County Museum

© Jurassic Coast Trust

The Jurassic Coast Gallery is a walk through time charting 95 miles of coastline from Exmouth in Devon to Old Harry Rocks in Dorset. The giant jaws of a huge marine reptile are on display here, with a 2.4 metre long skull and razor-sharp teeth, the Weymouth Bay Pliosaur is aptly named ‘The World’s Biggest Bite’.

The Dinosaur Museum

Dinosaur Museum

Just a couple minutes’ walk away, The Dinosaur Museum is devoted to the fascinating world of dinosaurs and is the perfect place for younger visitors. Life-size reconstructions and real fossils and dinosaur skeletons make for an exciting visit with hands-on displays that feature everything prehistoric.

Rotunda Museum

Image courtesy of Scarborough Museums Trust

Scarborough’s bastion of geology is a must-visit for anyone wanting to understand the dino-history of Yorkshire. The Dinosaur Coast Gallery offers a bright, colourful and resolutely family-friendly experience which explores the coastline and its treasures.

World Museum

© Mark McNulty

Lifesize casts of famous dinosaurs including a Megalosaurus and the fearsome Allosaurus await visitors to the Dinosaur Gallery of the World Museum in Liverpool. There are also fossilised reptile footprints, dinosaur poo and bones – and the occasional visit from a young T. rex.

The Great North Museum: Hancock

Image: Colin Davison © Tyne & Wear Archives & Museums

A full size T. rex skeleton in Fossil Stories makes this museum great for dinosaur enthusiasts. Have a go at being a palaeontologist by re-building prehistoric creatures and explore hundreds of exciting fossil plants and animals.

Oxford University Museum of Natural History

‘Oxford University Museum of Natural History’ © Magnus D (CC BY 2.0)

Visitors to Oxford University’s gothic-style natural history museum are greeted by the towering skeletons of an Iguanodon and T. rex, who guard the museum’s centre aisle. As well as these imposing specimens the museum is also home to four dinosaurs found within Oxfordshire – including two very rare complete skeletons – and a variety of other species of prehistoric reptiles.


Kelvingrove Art Gallery and Museum

‘Snappy’ © Ianan (CC BY-NC-ND 2.0)

Amid the many wonders in this something-for-everyone museum is the Creatures of the Past Gallery, which puts the dinosaurs that once roamed Scotland into context. The museum has 8000 astonishing objects and dinosaur and fossil lovers will be pleased to know the collection includes a 2.6 metre skeleton of Stenopterygius, crocodilian remains and an almost complete shell of a Jurassic turtle.

Sedgwick Museum of Earth Sciences

‘Sedgwick Museum of Earth Sciences, Cambridge’ © Miles Banbery (CC BY-NC 2.0)

Iggy the enormous Iguanodon skeleton guards the entrance to this museum, which is home to 1.5 million fossil, rock and mineral specimens from around the world. Explore 12 different galleries from the Ice Age to the Cambrian period and journey more than 500 million years through the history of life on Earth.


Source: http://museumcrush.org


170-million year old jawbone of dog-sized crocodile found Isle of Skye

Saturday, January 6, 2018

170-million year old jawbone of dog-sized crocodile found Isle of Skye

A new discovery of fossil has been added to the paleontologists’ knowledge graph by a team from the University of Edinburgh that found a rare 170 million-year-old jawbone.

Interestingly, the tiny bone is from 30-year old dog-sized crocodile-like creature spotted at Isle of Skye, Scotland. Scientists have made some X-ray scans to examine the previously found fossil. While measuring the bone of 3.5cm length found at Duntulm Castle in the north of the island, they have solved several mysteries.

Resulting in the observations, researchers noted that the jawbone is from a crocodile relative. They also believe that neosuchians named creatures were being diverse at the time on shores.

Dialy Mail reported that Dr. Steve Brusatte from the School of GeoSciences of the University has told the website that they have earlier discovered the pieces of the crocodile on Skye, but the recent one is nicer. It is a nearly complete jawbone.

Paleontologists are assuming that this small dog-sized creature was of the time of dinosaurs living in the lagoons of ancient Skye.

Dr. Brusatte further added: “These were very ancient, very primitive relatives of today’s crocodiles. They would have looked more like scaly dogs than big scary alligators. One reason why the new fossil is so important is because it is one of the few crocodile fossils from the middle part of the Jurassic Period from anywhere in the world.”

“Skye is a unique window into the Middle Jurassic, as it is one of the few places globally that preserves fossils from this time.”

He explained: “There are some relatives in North America, Asia, and other parts of Europe, but from later in time.”

“If we had better fossils of Middle Jurassic from other parts of the world, we would probably find more of these small crocs. But Skye is one of the only games in town for Middle Jurassic fossils,” he added.

The Isle of Skye is one of the few places in the world where fossils from the Middle Jurassic Period can be found. In 2008, scientists revealed that the earliest turtles that were known to live in water had been discovered on the same island.

Fossils of the 164 million-year-old reptiles were found on a beach on the Strathaird peninsula in the south of the island. The discovery formed a missing link between ancient terrestrial turtles and their modern, aquatic descendants.

Experts say that Skye was covered in lagoons and filled with turtles, crocodiles, pterosaurs and dinosaurs during the Middle Jurassic period.

Recently, geologists got hold of an ‘alien’ mineral while exploring the volcanic rocks of the Skye. They believe that meteorite might have hit our Earth almost 60 million years ago. At first, the researchers thought that the rocks are nothing but volcanic flow deposits called ignimbrite. But when they examined the rock deeply, they found out that rare meteoritic minerals were present beneath a 60million year lava flow that had originated from an ancient volcanic eruption.


Source: tecake.in

Top Fossil Discoveries of 2017

Sunday, January 14, 2018

 Some of the best fossils of 2017. Composite: WILLIAM GRAF, University of Wisconsin – Madison/Erikkson et al 2017/Lukas Panzarin/Andrea Cau/Royal Tyrrell Museum of Palaeontology

The Lost Worlds Revisited team has been reflecting on a bumper twelve months of palaeontological discoveries. Overwhelmed with choice, we also asked on Twitter for other people’s favourite fossil finds of 2017. So here is a combination of those fossiliferous suggestions, alongside some of our personal favourites. Enjoy!

First life on earth

Some of the smallest fossil finds of 2017 were among the most controversial. In March, Matthew Dodd and colleagues described tiny tubes and filamentscomposed of iron oxide in rocks from Quebec, Canada dated between 3.77bn and 4.28bn years old. They interpreted them as the remains of bacteria living around hydrothermal vents, pushing the earliest evidence of biological activity to more than 3.77bn years ago, and conceivably even a staggering 500m years earlier. In September, Takayuki Tashiro and colleagues analysed graphite particles from rocks 3.95bn years old from northern Labrador, Canada. They concluded from isotope ratios that the carbon was biologically produced, although this interpretation was not shared by all researchers.

Finally, in research published mid-December, Bill Schopf and colleagues used the carbon isotope composition of microfossils in the 3.46bn year old Apex Chert, from Western Australia, to confirm their previously-disputed biological origins and even work out which groups of microbes were represented. Two species were primitive bacterial photosynthesizers, one was a methane-producing Archaean microbe, and two others were bacterial methane consumers. This impressive study shows that methane-cycling microbial communities were already established by 3.5bn years ago.


Halszkaraptorthe bird-like bombshell

2017 was a great year for paleontologists, and it was hard to keep up with all the fossil splendor coming at me from various angles. However, one that stood out is the recently described fossil of a theropod dinosaur - studied non-invasively with high-tech 3D scanning - that shows amazing bird-like features. 

The theory that birds descended from dinosaurs is now commonly accepted amongst vertebrate palaeontologist. The discovery of exquisitely well preserved fossils, such as those from Liaoning province in China, has shown us that many features we once reserved for birds, were actually widespread amongst theropod dinosaurs (the group of dinosaurs that ultimately gave rise to birds), including those that were not on the lineage towards birds.

But no one could have predicted Halszkaraptor escuillieia new species of non-avian theropod dinosaur from Mongolia (Cau et al., 2017). Its long neck, constituting 50% of the total snout-to-tail length and the longest for any Mesozoic theropod dinosaur, is reminiscent of that seen in some birds, particularly swans. Halszkaraptor forms a new group of dromaeosaurids, the Halszkaraptorinae, and its unusual morphology suggests a semi-aquatic lifestyle. Its flattened wing bones are also seen in penguins and other aquatic birds, and the large number of teeth indicate that it was a predator. Moreover, Halszkaraptor appears to be the first non-avian dinosaur who was able to move both on land and in the water. As the authors of the research state in their last paragraph, the peculiar looks of Halszkaraptor shows us how much of the diversity of dinosaurs remains to be undiscovered.


Borealopelta markmitchelli

This is a new armoured dinosaur (a relative of the famous ankylosaurus) whose discovery was first reported in these pages back in 2013 because of the exceptional circumstances around its discovery in northern Alberta. Spotted by an excavator crew as a dot on a hillside, this remarkable creature is a real rarity, a land living animal that had floated many miles out to sea before it sank, intact, was buried, and eventually recovery millions of years later. The rock in which it was entombed was exceptionally tough and the bones fragile, so it took museum preparator Mark Mitchell years to prepare. He was rewarded when the animal was finally named as a new species.

However, the fossil itself turned out to be more remarkable still than the circumstances around its death and fossilisation. Borealopelta is one of the best preserved dinosaurs ever discovered: not only is the main skeleton very nearly complete, but the huge number of bony spikes and plates that make up its armour are also preserved. Better yet, they retain their original positions, so it is possible to see how they line up and change along the body. Even better still, much of the armour retains the horny sheathes that covered it. The skin of the animal is brilliantly preserved and in such fidelity that work has already been published on the colours and patterns of Borealopelta, and the likely use of its huge shoulder spines in displays.


Shringasaurus, the ‘horned lizard of India’

Following the biggest mass extinction in Earth’s geological history, at the end of the Permian, evolution in the Triassic period was like a teenager who has just left home for the first time. Finding itself in a new world free of constraints, it became wildly experimental. Many of these wacky, chimeric combinations have never been repeated (similar to most people’s experience of the 1980s). Evolution likes to try everything at least once. 

In 2017, Shringasaurus indicus (‘horned lizard of India’) evidenced the singular nature of these Triassic lifeforms. This newly-found archosauromorph waddled on four sprawled legs across what is now India, around 240m years ago. It had two forward pointing horns on its head, at the end of a long neck and body. With a humped, powerful shoulder at the front and sinuous back-end with long tail, it was like the love-child of a rhino and a komodo dragon. At around three-and-a-half metres long, this chunky, odd-ball herbivore would have been analogous to the large bovid species of the modern world (cows). It has been suggested that the horns of Shringasaurus were used for sexual selection, as in cattle. Having found the partial remains of several Shringasaurus individuals of different ages and genders, researchers were able to say a lot about how this animal grew, and that the horns were sexually dimorphic – meaning that only male animals possessed them.

Triassic animals like Shringasaurus are vital to helping us understand the bigger evolutionary picture. They were part of the first ecosystems established after the end-Permian mass-extinction, giving us information about how life on earth recovers from disaster. They were also the predecessors of the major radiations of crocodiles, turtles, dinosaurs, and multiple now-extinct reptilian lineages that would succeed them. They were also fantastically weird; which is why at least one of them deserves to be in the top fossil discoveries of the year.


The giant fossil Bobbit worm

If you have read Frank Herbert’s science-fiction novel Dune, you are aware of sandworms: the colossal worm-like creatures that inhabit the desert planet Arrakis. Thankfully, us earthlings do not have to worry about being swallowed by giant worms, but jaw fossils found in the Devonian of Ontaria, Canada, show that giant worms did once exist on earth.

Websteroprion armstrongi (partially named after death metal bass player Alex Webster) is a new species of giant bristle worm (polychaete) described based on these partial jaw fossils. Despite being long and squishy, bristle worms have a decent fossil record. They have been present since the Paleozoic (541-251 million years ago) and extinct forms show a diversity of body plans. The specimens were collected back in 1994, by Derek K Armstrong of the Ontario Geological Survey at a remote location in Ontario, and had been stored at the Royal Ontario Museum. 

Of this new fossil bristle worm, only the jaws (the only hard part in these animals) are preserved. The fossil jaws may have measured over 1 cm in length. Granted, this does not sound particularly awe-inspiring, but in the world of worms, Websteroprion’s jaws are truly colossal, as fossil polychaete jaws generally measure 0.1-2mm. By extrapolating from the size of the jaw fossils, the authors of the study estimate that Websteroprion armstrongi could have been 1-2 meters in length, comparable to living ‘giant eunicid’ species, colloquially referred to as ‘Bobbit worms’. The jaw fragments indicate that the animal was adult, and as some polychaetes continue to grow as adults, W. armstrongi could have attained larger lengths. W. armstrongi has the largest known jaws from the worm fossil record, and demonstrates that gigantism, an ecologically important trait, was already present in worms by 400 million years ago. Furthermore, they show the importance of existing museum collections, as they may contain overlooked gems.


Antarcticeras nordenskjoeldi


2017 was a bumper year for palaeontological discoveries and I don’t think a week went by when the Lost Worlds Revisited team didn’t have plenty of options to write about. However, in addition to the glitzy and glamorous headline-making discoveries, 2017 was also a good year for the more humble additions to species lists, taxonomic clean-ups and the palaeontological quiet work that happens away from the exceptionally preserved fossils and dino discoveries. This time of year I love looking through Wikipedia’s summaries of the year in palaeontology for the discoveries big and small and I must confess that my top fossil this year one I didn’t hear about when it was published back in March this year.

My pick for this year is a new species of Eocene cephalopod (the group containing octopuses, cuttlefish, nautiloids and ammonoids) from Antarctica, Antarcticeras nordenskjoeldi. The fossils themselves aren’t especially eye-catching and there isn’t a beautiful artistic reconstruction of the species accompanying the paper, however, it’s the interpretation of the fossils by colleagues in Sweden and Argentina that is noteworthy (Doguzhaeva et al. 2017). From details of the shell structure and position of the siphuncle (the tube that exchanges gases and fluids through shell chambers), A.nordenskjoeldi has been interpreted as a new species, in a new family, in a new order and amazingly the sole known member in a new cephalopod subclass, the Paracoleoidea.

This is a potentially huge new finding, adding a major new group of cephalopods alongside the four major and stable divisions, and the authors suggest that fossils of A.nordenskjoeldi represent a third way that soft bodied cephalopods evolved an internal shell in parallel with cuttlefish and ram’s horn squid. Fortunately, the paper itself is open access so you can take a look yourself, but the implication here, to borrow Internet parlance, is HUGE if true. It’s a bold interpretation, which is sometimes needed in science and time will tell if the Paracoleoidea will be accepted or rejected. So far the findings don’t seem to have created that many ripples in cephalopod palaeontology. Were this an equivalent suggestion in mammals or dinosaurs the paper would have garnered a huge amount of attention (as we saw with the ‘lower level’ saurischian/ornithischian research this year) but as it’s a relatively obscure group in the humble cephalopods this research risks fading into obscurity rather than cause a re-evaluation of cephalopod evolution.




Brown CM, Henderson DM, Vinther J, Fletcher I, Sistiaga A, Herrera J, Summons R. 2017. An exceptionally preserved three-dimensional, armored dinosaur reveals insights into coloration and Cretaceous predator-prey dynamics. Current Biology 27(16):2514-2521.

Cau A, Beyrand V, Voeten DFAE, Fernandez V, Tafforeau P, Stein K, Barsbold R, Tsogtbaatar K, Currie PJ, Godefroit P. 2017. Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaur. Nature 552: 395–399.

Doguzhaeva LA, Bengtson S, Reguero MA, Mörs T (2017) An Eocene orthocone from Antarctica shows convergent evolution of internally shelled cephalopods.PLoS ONE 12(3).

Eriksson, M., et al., 2017. Earth’s oldest ‘Bobbit worm’ – gigantism in a Devonian eunicidan polychaete. Scientific Reports 7:43061.

Sengupta S, Ezcurra MD, Bandyopadhyay S. 2017. A new horned and long-necked herbivorous stem-archosaur from the Middle Triassic of India. Scientific Reports. 7: 8366


Source: www.theguardian.com

Paleontologist Discover a 150 Million Years Old Plesiosaur in Antarctica

Sunday, December 24, 2017

Paleontologist Discover a 150 Million Years Old Plesiosaur in Antarctica

It is the first record of a plesiosaur from the Jurassic period in Antarctica. It is a carnivorous reptile of the sea that exceeded six meters in length. It was discovered in the Antarctic Peninsula, in a new paleontological site located 113 kilometers southwest of the Marambio Base in the Seymour Island.

The palaeontologist José Patricio O’Gorman, researcher at the Museo de la Plata (MLP) and CONICET, told to the Agencia CTyS-UNLaM that “this plesiosaur record is 80 million years older than what was known for Antarctica”.

“It was the first paleontological campaign that we conducted in this outcrop that is like a frozen sea of 150 million years in an excellent state of conservation”, said the lead author of the study that was accepted to be published in the scientific journal Comptes Rendus Palevol.

Dr. Soledad Gouiric Cavalli, MLP and CONICET specialist in the study of Jurassic fish, claimed that “when walking through the site you can find a great diversity of fish, ammonites, some bivalves, but we did not expect to find a plesiosaur of such age; It was surprising”.

“The finding is quite extraordinary because in the site there is not the kind of rocks in which you can find preserved materials in three dimensions, as is the case of the vertebrae of this marine reptile”, explained the researcher.

This outcropping of the Jurassic has a size of four kilometres long and two kilometres wide and it can only be reached after two hours of helicopter flight from the Marambio Base, so the researchers highlighted the logistics promoted by the Argentine Antarctic Institute (IAA).

campamento 750

There, during the 2016 summer Antarctic campaign, Dr. Gouiric Cavalli, Dr. José O’Gorman and the technicians Juan José Moly and Leonel Acosta Burllaile camped for 40 days. “It was very exciting to get there, to a place that nobody had stepped on in 23 years”, O’Gorman said.

“It is the furthest place where we have arrived with vertebrate palaeontology campaigns in Antarctica”, alleged Dr. Soledad Gouiric Cavalli. She added: “The Argentine campaigns are usually carried out in the vicinity of the Marambio Base (in the Marambio, James Ross and Vega Islands), but here we have expanded the range of action and we are interested in going to places even further away”.

Dr. Marcelo Reguero, researcher of the MLP and director of the paleontological campaigns of the Instituto Antártico Argentino (Argentine Antarctic Institute – IAA), said that “it was necessary to make a lot of logistics to get to this new paleontological site located in Cape Longing and the result was very successful, have rescued a great diversity of fish, plants and this plesiosaurus, and this summer we will go to the new campaign with even greater expectations”.

“In the 2016 campaign, a large number of fossils was obtained and for the expedition next summer we will go with instruments to obtain an even greater number of specimens”, anticipated the researcher of the MLP and the IAA.

Dr. Gouiric Cavalli, who will be part of the new campaign to be held in this frozen Jurassic sea from January 8 to mid-February, indicated that “there is a surprising amount of fish there and it is logical to think that the plesiosaurus that we discovered would feed on them, because it is a large marine reptile and we found medium-sized fish, some smalls, and some quite large too”.

About the excellent conservation of this fauna and marine flora of the Jurassic, the MLP and CONICET researcher explained that “they were preserved because the bottom of that sea had very little oxygen, so there were no organisms that could dismantle those specimens and the phenomenon of putrefaction did not take place either “.

The world 150 million years ago


Dr. Marcelo Reguero stated that “these rich and unique deposits in marine Jurassic vertebrates belong to the time when Antarctica was part of the Gondwana continent and was next to Australia, New Zealand, India, Madagascar, Africa and South America”.

150 million years ago the temperature of the seas was much higher and the world map was very different. According to Dr. José O’Gorman, this plesiosaurus, besides being the first of its kind in the Jurassic in Antarctica, serves as evidence in favour of the possibility of the dispersal of these reptiles by means of a passage that existed between Africa and Antarctica, which at that time had just separated.

Source: tecake.in

A 508-Million-Year-Old Sea Predator With a ‘Jackknife’ Head

Sunday, December 24, 2017

Habelia optata

Paleontologists at the University of Toronto (U of T) and the Royal Ontario Museum (ROM) in Toronto have entirely revisited a tiny yet exceptionally fierce ancient sea creature called Habelia optata that has confounded scientists since it was first discovered more than a century ago.

The research by lead author Cédric Aria, recent graduate of the PhD program in the department of ecology & evolutionary biology in the Faculty of Arts & Science at U of T, and co-author Jean-Bernard Caron, senior curator of invertebrate paleontology at the ROM and an associate professor in the departments of ecology & evolutionary biology and Earth sciences at U of T, is published today in BMC Evolutionary Biology.

Approximately 2 cm in length with a tail as long as the rest of its body, the long-extinct Habelia optata belongs to the group of invertebrate animals called arthropods, which also includes such familiar creatures as spiders, insects, lobsters and crabs. It lived during the middle Cambrian period approximately 508 million years ago and comes from the renowned Burgess Shale fossil deposit in British Columbia. Habelia optata was part of the “Cambrian explosion,” a period of rapid evolutionary change when most major animal groups first emerged in the fossil record.

Like all arthropods, Habelia optata features a segmented body with external skeleton and jointed limbs. What remained unclear for decades, however, was the main sub-group of arthropods to which Habelia belonged. Early studies had mentioned mandibulates—a hyperdiverse lineage whose members possess antennae and a pair of specialized appendages known as mandibles, usually used to grasp, squeeze and crush their food. But Habelia was later left as one of the typically unresolved arthropods of the Burgess Shale.

The new analysis by the U of T-ROM researchers suggests that Habelia optata was instead a close relative of the ancestor of all chelicerates, the other sub-group of arthropods living today, named for the presence of appendages called chelicerae in front of the mouth and used to cut food. This is mostly due to the overall anatomy of the head in Habelia, and the presence of two small chelicerae-like appendages revealed in these fossils.

Habelia now shows in great detail the body architecture from which chelicerates emerged, which allows us to solve some long-standing questions,” said Aria, who is now a post-doctoral researcher at the Nanjing Institute of Geology and Palaeontology, in China. “We can now explain why, for instance, horseshoe crabs have a reduced pair of limbs – the chilaria – at the back of their heads. Those are relics of fully-formed appendages, as chelicerates seem to originally have had heads with no less than seven pairs of limbs.”

 Fossil specimen of Habelia optata from the Royal Ontario Museum. This specimen spectacularly shows some of the very large jaws under the head shield. Note also the long dorsal spines on the thorax. Credit: Jean-Bernard Caron. Copyright: Royal Ontario Museum

Aria and Caron analyzed 41 specimens in total, the majority of which are new specimens acquired by ROM-led fieldwork parties to the Burgess Shale.

The research illustrates that the well-armoured body of Habelia optata, covered in a multitude of different spines, was divided into head, thorax and post-thorax, all bearing different types of appendages. The thorax displays five pairs of walking legs, while the post-thorax houses rounded appendages likely used in respiration.

“Scorpions and the now-extinct sea scorpions are also chelicerates with bodies divided into three distinct regions,” Aria explained. “We think that these regions broadly correspond to those of Habelia. But a major difference is that scorpions and sea scorpions, like all chelicerates, literally ‘walk on their heads,’ while Habelia still had walking appendages in its thorax.”

The researchers argue that this difference in anatomy allowed Habelia to evolve an especially complex head that makes this fossil species even more peculiar compared to known chelicerates. The head of Habelia contained a series of five appendages made of a large plate with teeth for mastication, a leg-like branch with stiff bristle-like spines for grasping, and an elongate, slender branch modified as a sensory or tactile appendage.

“This complex apparatus of appendages and jaws made Habelia an exceptionally fierce predator for its size,” said Aria. “It was likely both very mobile and efficient in tearing apart its preys.”

The surprising outcome of this study, despite the evolutionary relationship of Habelia with chelicerates, is that these unusual characteristics led instead the researchers to compare the head of Habelia with that of mandibulates from a functional perspective. Thus, the peculiar sensory branches may have been used in a similar fashion as mandibulates use antennae. Also, the overlapping plate-like appendages in the middle series of five are shown to open and close parallel to the underside of the head—much as they do in mandibulates, especially those that feed on animals with hardened carapaces.

Simplified phylogeny (tree of life) showing the relationship of Habelia with other groups of arthropods. A new study by paleontologists at the University of Toronto and the Royal Ontario Museum shows that it is an early relative of chelicerates -- a group including spiders, scorpions, horseshoe crabs and mites. Credit: Cedric Aria

Lastly, a seventh pair of appendages at the back of the head seems to have fulfilled a function similar to that of “maxillipeds”—appendages in mandibulates that assist with the other head limbs in the processing of food. This broad correspondence in function rather than in evolutionary origin is called “convergence.”

“From an evolutionary point of view, Habelia is close to the point of divergence between chelicerates and mandibulates,” Aria said. “But its similarities with mandibulates are secondary modifications of features that were in part already chelicerate in nature. This suggests that chelicerates originated from species with a high structural variability.”

The researchers conclude from the outstanding  structure, as well as from well-developed walking legs, that Habelia optata and its relatives were active predators of the Cambrian sea floors, hunting for small shelly sea creatures, such as small trilobites—arthropods with hard, mineralized exoskeletons that were already very diverse and abundant during Cambrian times.

“This builds onto the importance of carapaces and shells for evolutionary change during the Cambrian explosion, and expands our understanding of ecosystems at this time, showing another level of predator-prey relationship and its determining impact on the rise of arthropods as we know them today,” said Caron, who was Aria’s PhD supervisor when the bulk of this research was completed.

“The appearance and spread of animals with shells are considered to be one of the defining characteristics of the Cambrian explosion, and Habelia contributes to illustrate how important this ecological factor was for the early diversification of chelicerates and arthropods in general.”

The findings are described in the study “Mandibulate convergence in an armoured Cambrian stem chelicerate,” where Habelia optata is brought to life by visual artist and scientific illustrator Joanna Liang with animations depicting the spectacular body architecture and complex feeding mechanism of this fossil. Liang collaborated with Aria and Caron to produce the animations as part of her master of science thesis in biomedical communications at U of T under supervisor Dave Mazierski.

More information: Cédric Aria et al, Mandibulate convergence in an armored Cambrian stem chelicerate, BMC Evolutionary Biology (2017). DOI: 10.1186/s12862-017-1088-7

Journal reference: BMC Evolutionary Biology

Provided by: University of Toronto

Source: phys.org