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[dinosaur] Elasmosaurid basicranium from Russia + crocodile limb musculature + Eocenochelus

Ben Creisler

Some recent non-dino papers:

Nikolay G. Zverkov, Alexander O. Averianov & Evgeny V. Popov (2017)
Basicranium of an elasmosaurid plesiosaur from the Campanian of European Russia.
Alcheringa (advance online publication)
doi:  http://dx.doi.org/10.1080/03115518.2017.1302508   

The braincase of elasmosaurid plesiosaurs is poorly known. Here, we describe the exceptionally well-preserved elasmosaurid basicranium from the Rybushka Formation (lower Campanian) of Saratov Province, Russia. The material provides new anatomical information and peculiar features: single anterior foramen for the cerebral carotid arteries, anteroposteriorly elongated sella turcica and deep canal on the basioccipital process. This allow us to reconstruct a carotid circulation in plesiosaurs and propose new basicranial features (anteroposteriorly elongated sella turcica and single anterior foramen for the cerebral carotids), which could be potentially synapomorphic for a clade within the Elasmosauridae.


Ada J. Klinkhamer, D. Ray Wilhite, Matt A. White & Stephen Wroe  (2017)
Digital dissection and three-dimensional interactive models of limb musculature in the Australian estuarine crocodile (Crocodylus porosus). 
PLoS ONE 12(4): e0175079. 

Digital dissection is a relatively new technique that has enabled scientists to gain a better understanding of vertebrate anatomy. It can be used to rapidly disseminate detailed, three-dimensional information in an easily accessible manner that reduces the need for destructive, traditional dissections. Here we present the results of a digital dissection on the appendicular musculature of the Australian estuarine crocodile (Crocodylus porosus). A better understanding of this until now poorly known system in C. porosus is important, not only because it will expand research into crocodilian locomotion, but because of its potential to inform muscle reconstructions in dinosaur taxa. Muscles of the forelimb and hindlimb are described and three-dimensional interactive models are included based on CT and MRI scans as well as fresh-tissue dissections. Differences in the arrangement of musculature between C. porosus and other groups within the Crocodylia were found. In the forelimb, differences are restricted to a single tendon of origin for triceps longus medialis. For the hindlimb, a reduction in the number of heads of ambiens was noted as well as changes to the location of origin and insertion for iliofibularis and gastrocnemius externus.


Eocenochelus gen. nov.

Pérez-García, Adán, de Lapparent de Broin, France, and Murelaga, Xabier. 2017. 
The Erymnochelys group of turtles (Pleurodira, Podocnemididae) in the Eocene of Europe: New taxa and paleobiogeographical implications. 
Palaeontologia Electronica 20.1.14A: 1-28
doi: palaeo-electronica.org/content/2017/1798-erymnochelys-group-in-europe

The Erymnochelys group is a lineage of Erymnochelyinae, pleurodiran turtles that originated in Africa, with a fossil record extending from the Late Cretaceous. It is currently represented by a single species, the Malagasy Erymnochelys madagascariensis. Information on most of its fossil representatives is sparse. In fact, the oldest unambiguous generic determinations heretofore established within the group are those of Turkanemys and Kenyemys, both from the latest Miocene-Pliocene of Kenya. The description and illustration of the French middle Eocene species ‘aff. Erymnochelys’ eremberti is completed here, and a diagnosis for this species is proposed for the first time. It is attributed to a new genus, Eocenochelus, the first genus of the Erymnochelys group defined outside of Africa. Eocenochelus is also recognized in the European lower and upper Eocene record by two new species, Eocenochelus lacombianus and Eocenochelus farresi, respectively. Therefore, Eocenochelus is a taxon with a wide distribution in Europe during the Eocene and is relatively diverse. This is also the case with the continental Neochelys, the only other podocnemidid genus so far recognized in the European Paleogene record. Exclusively identified in coastal deposits, Eocenochelus is the only known form of the Erymnochelys group found in marginal marine sediments. Its anatomical adaptations probably facilitated the spread from Africa to Europe.