In: Journal of Vertebrate Paleontology, 2015, vol. 35, no. 2, p. e909450
A new turtle from the Early Cretaceous (Aptian) Jiufotang Formation of western Liaoning, China, Perochelys lamadongensis, gen. et sp. nov., represents the first species of soft-shelled turtle from the Jehol Biota. The new taxon is diagnosed by the combination of the following characters: nuchal bone about five times wider than long; preneural absent; reversal of the orientation in the neural...
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In: Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, 2015, p. -
The origin of turtles and their unusual body plan has fascinated scientists for the last two centuries. Over the course of the last decades, a broad sample of molecular analyses have favored a sister group relationship of turtles with archosaurs, but recent studies reveal that this signal may be the result of systematic biases affecting molecular approaches, in particular sampling, non-randomly...
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In: Proceedings of the Royal Society of London B: Biological Sciences, 2015, vol. 282, no. 1798, p. 20141013
Calibration is the rate-determining step in every molecular clock analysis and, hence, considerable effort has been expended in the development of approaches to distinguish good from bad calibrations. These can be categorized into a priori evaluation of the intrinsic fossil evidence, and a posteriori evaluation of congruence through cross-validation. We contrasted these competing approaches and...
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In: Systematic Biology, 2014, p. syu072
The unique ability of modern turtles to retract their head and neck into the shell through a side-necked (pleurodiran) or hidden-necked (cryptodiran) motion is thought to have evolved independently in crown turtles. The anatomical changes that led to the vertebral shapes of modern turtles, however, are still poorly understood. Here we present comprehensive geometric morphometric analyses that...
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In: Bulletin of the Peabody Museum of Natural History, 2014, vol. 55, no. 2, p. 201–214
Fossil carettochelyine turtles are well known from the Paleogene of Europe (Allaeochelys), North America and Asia (Anosteira); however, the previously known Neogene fossil record is highly fragmentary and was therefore unsuitable for taxonomic analysis. In this work, we present a new carettochelyine taxon, Allaeochelys libyca, from the Middle Miocene (Langhian) of Gebel Zelten (Libya) based on an...
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In: Journal of Vertebrate Paleontology, 2014, vol. 34, no. 2, p. 353–374
The fossil turtle Tropidemys langii is a representative of Plesiochelyidae, a traditionally recognized group of Late Jurassic turtles diagnosed by the presence of three cervical scutes and adapted to life in the sea. Tropidemys langii was previously only known from fossilized carapaces and, possibly, plastra from Europe, most notably the famous ‘Solothurn Turtle Limestone’ of Switzerland. Due...
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In: Journal of Vertebrate Paleontology, 2014, vol. 34, no. 2, p. 327–352
A complete description of the xinjiangchelyid turtles Annemys levensis and A. latiens is provided, based on all available material from the Upper Jurassic type locality of Shar Teg, Mongolia. Annemys latiens was previously known almost exclusively from shell material, but an undescribed skull from Shar Teg is referable to this species and its distinct morphology confirms the presence of two taxa...
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In: BMC Evolutionary Biology, 2014, vol. 14, no. 1, p. 77
Background: Manchurochelys manchoukuoensis is an emblematic turtle from the Cretaceous Yixian Formation of Liaoning, China, a geological rock unit that is famous for yielding perfectly preserved skeletons of fossil vertebrates, including that of feathered dinosaurs. Manchurochelys manchoukuoensis was one of the first vertebrates described from this fauna, also known as the Jehol Biota. The...
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In: Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, 2014, p. -
Turtles have the unparalleled ability to retract their heads and necks within their shell but little is known about the evolution of this trait. Extensive analysis of neck mobility in turtles using radiographs, CT scans, and morphometry reveals that basal turtles possessed less mobility in the neck relative to their extant relatives, although the anatomical prerequisites for modern mobility were...
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In: Journal of Anatomy, 2013, vol. 223, no. 5, p. 421–441
The hooked element in the pes of turtles was historically identified by most palaeontologists and embryologists as a modified fifth metatarsal, and often used as evidence to unite turtles with other reptiles with a hooked element. Some recent embryological studies, however, revealed that this element might represent an enlarged fifth distal tarsal. We herein provide extensive new myological and...
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