Jucha squalea: Paleontologists Identify New Species of Plesiosaur

A new genus and species of elasmosaurid plesiosaur has been identified by an international team of paleontologists led by Dr. Valentin Fischer from the Evolution & Diversity Dynamics Lab at the Université de Liège.

Jucha squalea swam the world’s oceans during the Early Cretaceous period, approximately 130 million years ago.

This marine reptile belongs to Elasmosauridae, a family of plesiosaurs characterized by extremely long necks and slim bodies.

“Plesiosaurian marine reptiles evolved a wide range of body shapes during the Jurassic and Cretaceous, including long-necked forms,” Dr. Fischer and colleagues wrote in their paper.

“Many Late Cretaceous members of the Elasmosauridae clade epitomized this part of the plesiosaurian morphological spectrum by evolving extremely long necks through somitogenesis (resulting in an increase in the number of cervical centra) and differential growth (resulting in the elongation of cervical centra).”

“However, the early evolution of elasmosaurids remains poorly understood because of a generally poor Lower Cretaceous fossil record.”

The partial skeleton of a mature individual of Jucha squalea was unearthed in 2007 in the vicinity of the Slantsevy Rudnik village near Ulyanovsk in Eastern Europe.

“Jucha squalea represents one of the geologically oldest occurrences of elasmosaurids,” the paleontologists wrote.

“It lacks a series of features that otherwise characterize the group, such as the pectoral bar and the heart-shaped intercoracoid fenestra, and thus documents some of the earliest stages of the elasmosaurid radiation.”

“Jucha squalea marks an early attempt at cervical elongation in elasmosaurids via differential growth, possessing anterior cervical centra that are much more elongated than those of other early xenopsarians,” they added.

“The cervical shape values we gathered suggest that elasmosaurids underwent multiple episodes of cervical shortening, notably during the Early Cretaceous.”

The team’s paper was published online in the Zoological Journal of the Linnean Society.

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Valentin Fischer et al. A new elasmosaurid plesiosaurian from the Early Cretaceous of Russia marks an early attempt at neck elongation. Zoological Journal of the Linnean Society, published online October 16, 2020; doi: 10.1093/zoolinnean/zlaa103

Source: www.sci-news.com/