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[dinosaur] Nothosaurus skull + Shirerpeton, new albanerpetontid from Japan + last terror bird from Uruguay + more

Ben Creisler

Some recent non-dino papers:

Free pdf:

Dennis F. A. E. Voeten, Tobias Reich, Ricardo AraÃjo & Torsten M. Scheyer (2018)Â
Synchrotron microtomography of a Nothosaurus marchicus skull informs on nothosaurian physiology and neurosensory adaptations in early Sauropterygia.Â
PLoS ONE 13(1): e0188509.Â
doi: https://doi.org/10.1371/journal.pone.0188509

Nothosaurs form a subclade of the secondarily marine Sauropterygia that was well represented in late Early to early Late Triassic marine ecosystems. Here we present and discuss the internal skull anatomy of the small piscivorous nothosaur Nothosaurus marchicus from coastal to shallow marine Lower Muschelkalk deposits (Anisian) of Winterswijk, The Netherlands, which represents the oldest sauropterygian endocast visualized to date. The cranial endocast is only partially encapsulated by ossified braincase elements. Cranial flattening and lateral constriction by hypertrophied temporal musculature grant the brain a straight, tubular geometry that lacks particularly well-developed cerebral lobes but does potentially involve distinguishable optic lobes, suggesting vision may have represented an important sense during life. Despite large orbit size, the circuitous muscular pathway linking the basisphenoidal and orbital regions indicates poor oculomotor performance. This suggests a rather fixed ocular orientation, although eye placement and neck manoeuvrability could have enabled binocular if not stereoscopic vision. The proportionally large dorsal projection of the braincase endocast towards the well-developed pineal foramen advocates substantial dependence on the corresponding pineal system in vivo. Structures corroborating keen olfactory or acoustic senses were not identified. The likely atrophied vomeronasal organ argues against the presence of a forked tongue in Nothosaurus, and the relative positioning of external and internal nares contrasts respiratory configurations proposed for pistosauroid sauropterygians. The antorbital domain furthermore accommodates a putative rostral sensory plexus and pronounced lateral nasal glands that were likely exapted as salt glands. Previously proposed nothosaurian âforamina eustachiiâ arose from architectural constraints on braincase development rather than representing functional foramina. Several modifications to brain shape and accessory organs were achieved through heterochronic development of the cranium, particularly the braincase. In summary, the cranium of Nothosaurus marchicus reflects important physiological and neurosensory adaptations that enabled the groupâs explosive invasion of shallow marine habitats in the late Early Triassic.


Free pdf:

Shirerpeton isajii gen. et sp. nov.

Ryoko Matsumoto & Susan E. Evans (2018)Â
The first record of albanerpetontid amphibians (Amphibia: Albanerpetontidae) from East Asia.Â
PLoS ONE 13(1): e0189767.
doi: https://doi.org/10.1371/journal.pone.0189767

Albanerpetontids are an enigmatic fossil amphibian group known from deposits of Middle Jurassic to Pliocene age. The oldest and youngest records are from Europe, but the group appeared in North America in the late Early Cretaceous and radiated there during the Late Cretaceous. Until now, the Asian record has been limited to fragmentary specimens from the Late Cretaceous of Uzbekistan. This led to speculation that albanerpetontids migrated into eastern Asia from North America in the Albian to Cenomanian interval via the Beringian land bridge. However, here we describe albanerpetontid specimens from the Lower Cretaceous Kuwajima Formation of Japan, a record that predates their first known occurrence in North America. One specimen, an association of skull and postcranial bones from a single small individual, permits the diagnosis of a new taxon. High Resolution X-ray Computed Microtomography has revealed previously unrecorded features of albanerpetontid skull morphology in three dimensions, including the presence of a supraoccipital and epipterygoids, neither of which occurs in any known lissamphibian. The placement of this new taxon within the current phylogenetic framework for Albanerpetontidae is complicated by a limited overlap of comparable elements, most notably the non-preservation of the premaxillae in the Japanese taxon. Nonetheless, phylogenetic analysis places the new taxon closer to Albanerpeton than to Anoualerpeton, Celtedens, or Wesserpeton, although Bootstrap support values are weak. The results also question the monophyly of Albanerpeton as currently defined.



Jozef Klembara, Miroslav Hain & Andrej ÄerÅanskà Â(2017)

The first record of anguine lizards (Anguimorpha, Anguidae) from the early Miocene locality Ulm â Westtangente in Germany.

Historical Biology (advance online publication)

doi:Â https://doi.org/10.1080/08912963.2017.1416469ÂÂ




The first fossil anguine material from the lower Miocene (MN 2) locality Ulm â Westtangente in Germany is described. The parietal and compound bone of the lower jaw can be attributed to Ophisaurus holeci, previously known only from younger age (MN 3âMN 7). Moreover, the parietal represents the largest parietal of this species. In other disarticulated material, such as frontal, maxilla, dentary and osteoderms, alpha taxonomy is not possible and these elements cannot be allocated at the species level. Despite a limited data source, a phylogenetic analysis was done (16 taxa, 36 characters) producing four equally parsimonious trees. The analysis shows a close relationship of O. holeci and the Eocene Ophisauriscus quadrupes. These two taxa form a monophyletic clade, a sister-clade to Ophisaurus + Anguis. However, more complete skeletal material of O. holeci is needed to support such a statement. We used our phylogenetic analysis to analyze trace character history for one frontal and three parietal characters. The palaeoenvironmental conditions of the locality Ulm â Westtangente bring further support of the previous hypothesis that O. holeci was adapted to environments with high ground water levels â environments around lakes or rivers.


Washington Jones, AndrÃs Rinderknecht, Herculano Alvarenga, Felipe Montenegro & MartÃn Ubilla (2018)
The last terror birds (Aves, Phorusrhacidae): new evidence from the late Pleistocene of Uruguay.
PalZ (advance online publication)
DOI: https://doi.org/10.1007/s12542-017-0388-y

We report new fossil evidence of terror bird survival until the end of the Pleistocene in Uruguay. The new specimens comprise the distal portion of right tarsometatarsus and a left humerus; the latter is assigned to the genus Psilopterus. The sedimentary context of the remains yields a characteristic Pleistocene mammalian association along with numerical age dating giving an undoubted late Pleistocene age (OSL 96,040 Â 6300 years). We also revise and discuss the systematic placement of late Pleistocene phorusrhacid material previously published. The trophic role of terror birds and other South American carnivorous birds in late Pleistocene ecosystems should be revised based on the increasing findings of avian fossil materials.

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