Paleontologists say they have identified a new species of marine reptile in the ophthalmosaurid family Platypterygius. It lived about 125 million years ago.
Ophthalmosauridae is a family of ichthyosaurs that lived during the Jurassic and Cretaceous periods.
These ichthyosaurs appeared around the world during the early Bajosian period, about 170 million years ago, after which most other ichthyosaur lineages disappeared during the late Toarthian period, 174 million years ago.
Two lineages of Ophthalmosauridae are known. One contains two genera, Agilosaurus and Ophthalmosaurus, and the other contains three genera: Brachypterygius, Caprisaurus, and Platypterygius.
The newly identified species is Platypterygius elsuntuoso, belonging to the latter genus.
This marine reptile swam in the early Barremian seas, about 125 million years ago.
“The morphology of the new specimen is consistent with diagnostic features of Platypterygius, supporting its inclusion in this genus,” said lead author Dr. María Paramo Fonseca and colleagues from the National University of Colombia and the National Geological Museum José Royo y Gómez.
“The difference between this specimen and all others in the Platypterygius genus supports the establishment of the new species, Platypterygius elsuntuoso.”
Platypterygius elsuntuoso holotype. Scale bar – 10 cm. Image credit: Paramo Fonseca others, doi: 10.15446/esrj.v28n2.112332.
Fossilized remains of a juvenile or subadult Platypterygius elsuntuoso were collected in 1999 by researchers at the Columbia Geobiological Foundation.
The specimen consists of a nearly complete skull, several axial elements including the atlantoaxial and several cervical vertebrae, the left coracoid, and several phalanges.
“This specimen was discovered in a concretion in the La Cabrera hill northwest of Villa de Leyva (Boyaca, Colombia), where the Arcilolitas Abigaladas Formation of the Paja Formation is exposed,” the paleontologists said.
“Because its exact geographic origin is unknown, its exact stratigraphic position could not be determined.”
“However, numerous ammonoid specimens have been extracted from the same stone, some of which have been preliminarily identified as ammonoid specimens of Acanthopticoceras.”
The researchers made morphological comparisons of Platypterygius elsuntuoso with ophthalmosaur ichthyosaurs of the Cretaceous and Late Jurassic periods.
They also revised the genus Platypterygius based on published descriptions and first-hand observations of Colombian materials.
“We have come to the conclusion that Platypterygius is a genus distinguished by a distinctive forelimb structure and a specific combination of cranial features,” they said.
“We revised that diagnosis to accept that Barremian to lower Cenomanian species are valid: Platypterygius platydactylus, Platypterygius americanus, Platypterygius australis, Platypterygius hercinus, Platypterygius sachicarum, Platypterygius virjucobi, and the new species Platypterygius elsuntuoso.”
“Therefore, Platypterygius was a cosmopolitan genus that diversified as it conquered oceans from the Early Cretaceous to the Early Late Cretaceous.”
The discovery of Platypterygius elsuntuoso is reported in a paper in Earth Science Research Journal.
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Maria E. Paramo-Fonseca others. 2024. new species Platypterygius Evaluation of the species composition of (Ophthalmosauridae) and their genera from the Lower Barremian of Columbia. Earth Science Resolution J 28 (2): 103-126;doi: 10.15446/esrj.v28n2.112332
Source: www.sci.news
