Life reconstruction of the mosasaur Plioplatecarpus, a distant relative of Sarabosaurus dahli.
Image credit: Sci.News / Dmitry Bogdanov.
The chronic problem for creationists, and one the frauds who lead their cult need to work ever harder to give their dupes strategies for ignoring, is that being a counter-factual superstition, the facts keep trying to assert themselves and create doubt in the minds of the faith-fooled.
Another such fact is the discovery that the fossil remains of an early marine reptile, a mosasaur, found 11 years ago, have, on re-examination, proved to be close to the stem mosasaur of this group of extinct marine reptiles and gives clues about the origins of a novel cranial blood supply seen in a particular group of mosasaurs. The species has been named Sarabosaurus dahli after the US Bureau of Land Management volunteer, Steve Dahl, who helped recover the fossil fragments.
The team of Dutch, French and American palaeontologists who identified the fossil as a new species included Dr. L. Barry Albright III, of the Department of Physics, University of North Florida, Jacksonville, Florida, U.S.A., and, embarrassingly for Creationists, Dr. Michael J. Polcyn, of the Southern Methodist University, Dallas, Texas, who obviously has no difficulty accepting that the TOE best explains the observable evidence.
The finding and its significance are explained in a University of North Florida news release:
University of North Florida faculty member Dr. Barry Albright is part of a research team led by the Bureau of Land Management (BLM) who have unlocked new evolutionary information following the discovery of a 94-million-year-old mosasaur in the gray shale badlands of the National Park Service Glen Canyon National Recreation Area in southern Utah. Mosasaurs are fully marine-adapted reptiles that swam the seas while dinosaurs ruled the land. The ground-breaking research was just published in Cretaceous Research.
The journey began nearly 11 years ago as Scott Richardson, a trained volunteer working under Dr. Albright, searched for fossilized remains of creatures that once swam in a vast seaway that covered most of the middle of North America during the Late Cretaceous Period, between 84 and 95 million years ago. In March 2012, Richardson found numerous small skull fragments and vertebrae of what proved to be an early mosasaur scattered across a broad shale slope.
A joint team from the BLM and National Park Service recovered nearly 50% of the specimen over the course of the next two field seasons, enough to determine its exact identity. Dr. Alan Titus, BLM Paria River District paleontologist, led a crew of BLM staff and volunteers on the research. The team included volunteer Steve Dahl who was later honored in the species name, Sarabosaurus dahli, or “Dahl’s reptile of the mirage.” The name alludes to both the ancient seaway in which this animal swam that has long since vanished and the mirages that accompany the region’s extreme summer heat.During the time the Tropic Shale was being deposited, about 94 million years ago, mosasaurs were still very small, primitive, and in the early evolutionary stages of becoming fully marine adapted. For these reasons, their fossils are extremely rare and difficult to find.
Dr. L. Barry Albright III, co-author
Department of Physics
University of North Florida, Jacksonville, Florida, U.S.A.
Mosasaurs from younger rocks are relatively abundant, but mosasaurs are extremely rare in rocks older than about 90 million years. Finding one that preserves so much informative data, especially one of this age, is truly a significant discovery.
Dr. Alan Titus, co-author
Bureau of Land Management-Paria River District,
Kanab, Utah, U.S.A.The oldest mosasaurs are small, about 3 feet long, but they evolved into gigantic lizard-like marine predators that dominated the oceans during the latter part of the dinosaur age. Their land-dwelling ancestors were similar to the modern Komodo Dragon, but through time their aquatic cousins evolved streamlined bodies, paddle-like fins, and tails that propelled them through the water. Early forms were more lizard-like in appearance and retained relatively primitive tails and limbs, but Sarabosaurus possessed one important difference, a new way to circulate blood into its brain.Sarabosaurus sheds light on long-standing questions regarding the relationship of some early branching mosasaurid species, but also provides new insights into the evolution and antiquity of a novel cranial blood supply seen in a particular group of mosasaurs.
Dr. Michael J. Polcyn, corresponding author
Faculty of Geosciences
Utrecht University, Princetonlaan, the Netherlands
And Huffington Department of Earth Sciences
Southern Methodist University, Dallas, Texas, U.S.A.
Fig. 2. Schematic reconstruction of the skull of Sarabosaurus dahli gen. et sp. nov. showing preserved elements in (A) lateral, (B) dorsal, and (C) ventral views. Some elements mirrored from opposite side. Reconstructed portions based on Tethysaurus nopscai (SMU75486) and Russellosaurus coheni (SMU73056). (D) Isolated zygopophysis showing growth rings with relative topographic relief shown in the third panel with legend given in microns, and (E), broken edge of zygosphene showing laminar bone deposition, interpreted as corresponding to annual growth. Scale bars equal 10 cm for A-C and 1mm for D and E.
Fig. 3. Premaxilla of Sarabosaurus dahli gen. et sp. nov. in (A) dorsal, (B) ventral, (C) posterior, and (D) left lateral views. Anterior snout of Tethysaurus nopscai (SMU75486) in (E) dorsal view. Premaxilla of Russellosaurus coheni (SMU73056) in (F) dorsal view. Anterior snout of Yaguarasaurus columbianus (BRV-68) in (G) dorsal view. Abbreviations: al, alveolus; alb, alveolar bone; am.mal. anterior margin median alveolus; ef, ethmoid foramen; mal, median alveolus; pxn.pr, premaxilla nasal process; vmr, ventral median ridge. Scale bars equal 1cm.
The team's findings are published, open access in the journal,Cretaceous Research:
AbstractNot that these sorts of facts make any difference to the opinions of creationists who don't base them on facts but on dogma, childish superstition and the thinking bility of dim-witted toddler. Their beliefs are sacred so mere evidence can be waved aside in the childish belief that evidence ignored is evidence that isn't there.
We describe and name a new mosasaur taxon, Sarabosaurus dahli gen. et sp. nov., from the lower Turonian part of the Tropic Shale in Utah, USA. The holotype specimen preserves significant portions of the skull and axial postcranial skeleton. It was found in the upper part of the Watinoceras devonense Ammonite Zone, bounded by radioisotopic dates above and below, and is thus about 93.7 Ma, the oldest mosasaurid taxon known from the Western Interior Seaway. The new taxon possesses a vascular pattern of the basisphenoid heretofore only seen in late diverging plioplatecarpine mosasaurids. Reevaluation of the morphology of the basisphenoid of previously described Turonian mosasaurs using μCT techniques reveals the derived condition is also present in Yaguasaurus and the incipient condition in Tethysaurus and Russellosaurus. In these two taxa, the canals enter the basisphenoid, but do not pass into the basioccipital. Instead, they exit only high on the posterior wall of the sella turcica, in a position similar to the basilar artery of other lizards. This vascular pattern, both in its incipient and derived states, is unique among squamates and supports inclusion of the aforementioned taxa in a monophyletic Plioplatecarpinae, for which we provide an emended diagnosis. Phylogenetic analysis recovers Sarabosaurus dahli gen. et sp. nov. as the sister taxon to Yaguarasaurus and all other later diverging plioplatecarpines, with Russellosaurus and Tethysaurus as successive sister taxa. Tylosaurine mosasaurids retain the primitive condition of the basisphenoid vascularization pattern and implies a tylosaurine-plioplatecarpine divergence in the late Cenomanian or earliest Turonian.
Polcyn, M.J., Bardet, N., Albright III., L.B., Titus, A.,
A new lower Turonian mosasaurid from the Western Interior Seaway and the antiquity of the unique basicranial circulation pattern in Plioplatecarpinae
Cretaceous Research, https://doi.org/10.1016/j.cretres.2023.105621.
Copyright: ©2023 The authors.
Published by Elsevier B.V. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.