Friday, December 23rd, 2022

Time	Event
9:40a	[Paleontology • 2022] Annemys variabilis • Xinjiangchelyid Turtles from the Middle Jurassic of the Berezovsk Coal Mine (Krasnoyarsk Territory, Russia): Systematics, Skeletal Morphology, Variation, Relationships and Palaeobiogeographic Implications     Annemys variabilis  Obraztsova, Krasnolutskii, Sukhanov & Danilov, 2022 DOI: 10.1080/14772019.2022.2093662   twitter.com/JournalSystPal  Artwork by Alexander Ostroshabov. Abstract This paper is devoted to the description of a new species of xinjiangchelyid turtle – Annemys variabilis sp. nov. – represented by thousands of isolated bones and several more complete specimens from the Middle Jurassic (Bathonian) Itat Formation of the Berezovsk coal mine, Krasnoyarsk Territory, western Siberia, Russia. The description is based on a sample of the best-preserved specimens. The new species differs from other Annemys spp. by a combination of cranial and shell characters. The basisphenoids (about 200 specimens) of A. variabilis demonstrate variation in 12 characters, some of which are reported in turtles for the first time. About 20 shell characters of A. variabilis are subject to ontogenetic or interindividual variation. Some of these characters are variable in other Annemys spp. and other xinjiangchelyids. The formula of the cervical vertebrae [(2(3()4()5()6()7()8) or (2(3()4()5()6()7()8(] with two opisthocoelous vertebrae (2 and 3), four or five amphicoelous vertebrae (4–7 or 4–8), and one procoelous vertebra is unique for this species among xinjiangchelyids, which were previously known to have only amphicoelous cervicals. Other characters of the non-shell postcranium correspond to those of other xinjiangchelyids. Of the three phylogenetic analyses performed in this study, Analysis 1 does not support the monophyly of either Xinjiangchelyidae or Annemys, Analysis 2 shows paraphyly of Xinjiangchelyidae and monophyly of the Annemys clade (A. latiens, A. levensis, A. variabilis and A. wusu), and Analysis 3 supports monophyly of the Annemys clade with A. latiens, A. levensis and A. variabilis, only in the majority rule consensus tree. The diversity of the turtle assemblage of the Itat Formation is re-assessed as containing 2–3 taxa (A. variabilis [=Testudines indet. 2], Testudines indet. 1 and 3), which is in agreement with similar diversities seen in some other Middle Jurassic Asian turtle assemblages. The known record of Annemys spp. is restricted to the northern part of Asia. Annemys variabilis    Ekaterina M. Obraztsova, Sergei A. Krasnolutskii, Vladimir B. Sukhanov and Igor G. Danilov. 2022. Xinjiangchelyid Turtles from the Middle Jurassic of the Berezovsk Coal Mine (Krasnoyarsk Territory, Russia): Systematics, Skeletal Morphology, Variation, Relationships and Palaeobiogeographic Implications. Journal of Systematic Palaeontology. 20(1); 1-61. DOI: 10.1080/14772019.2022.2093662   twitter.com/JournalSystPal/status/1574689687608107010 (Comment on this)
2:54p	[Paleontology • 2022] 100 Million Years of Turtle Paleoniche Dynamics enable the Prediction of Latitudinal Range shifts in A Warming World  3 fossil turtles: Basilemys, Zangerlia and Axestemys are on the left half,  the extant turtles Geochelone, Trionyx and Carettochelys on the right half  in Chiarenza, Waterson, Schmidt, ... et Barrett, 2022.  DOI: 10.1016/j.cub.2022.11.056    twitter.com/AAlechiarenza illustration by Mauricio Anton.  Highlights:  • Non-marine turtles invaded higher paleolatitudes several times in the past • Non-marine turtles reached their highest latitudes in the Cenomanian and Eocene • Occupation of high paleolatitudes is projected at extreme emission scenarios • Human occupation at high latitudes may prevent turtle adaptation to climate change Summary Past responses to environmental change provide vital baseline data for estimating the potential resilience of extant taxa to future change. Here, we investigate the latitudinal range contraction that terrestrial and freshwater turtles (Testudinata) experienced from the Late Cretaceous to the Paleogene (100.5–23.03 mya) in response to major climatic changes. We apply ecological niche modeling (ENM) to reconstruct turtle niches, using ancient and modern distribution data, paleogeographic reconstructions, and the HadCM3L climate model to quantify their range shifts in the Cretaceous and late Eocene. We then use the insights provided by these models to infer their probable ecological responses to future climate scenarios at different representative concentration pathways (RCPs 4.5 and 8.5 for 2100), which project globally increased temperatures and spreading arid biomes at lower to mid-latitudes. We show that turtle ranges are predicted to expand poleward in the Northern Hemisphere, with decreased habitat suitability at lower latitudes, inverting a trend of latitudinal range contraction that has been prevalent since the Eocene. Trionychids and freshwater turtles can more easily track their niches than Testudinidae and other terrestrial groups. However, habitat destruction and fragmentation at higher latitudes will probably reduce the capability of turtles and tortoises to cope with future climate changes. Keywords: Testudinata, climate change, distribution, Late Cretaceous, Eocene, ecological niche modeling  3 fossil turtles: Basilemys, Zangerlia and Axestemys are on the left half,  the extant turtles Geochelone, Trionyx and Carettochelys on the right half  illustration by Mauricio Anton   Alfio Alessandro Chiarenza, Amy M. Waterson, Daniela N. Schmidt, Paul J.Valdes, Chris Yesson, Patricia A. Holroyd, Margaret E. Collinson, Alexander Farnsworth, David B. Nicholson, Sara Varela and Paul M. Barrett. 2022. 100 Million Years of Turtle Paleoniche Dynamics enable the Prediction of Latitudinal Range shifts in A Warming World. Current Biology. In Press DOI: 10.1016/j.cub.2022.11.056    twitter.com/AAlechiarenza/status/1605608429241901058 (Comment on this)

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