Triassic turtle tracks and the origin of turtles

Lichtig, Asher Jacob; Lucas, Spencer G.; Klein, Hendrik; Lovelace, David M.

doi:10.1080/08912963.2017.1339037

Cited by 39 publications

(20 citation statements)

References 28 publications

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“…Whether turtles are anapsid parareptiles ( Carroll, 1988 ) or they are diapsids and form a sister group of lepidosaurs, or archosaurs, or all the other diapsids (for a survey, see Iwabe et al, 2005 ), it is beyond the scope of our study; for recent opinions, see Lyson et al (2012) , Joyce (2015) , Adams et al (2016) , or Shaffer et al (2017) . In either case, the turtles are more ancient than Squamata ( Joyce, 2007 ; Lichtig et al, 2018 ).…”

Section: Discussionmentioning

confidence: 99%

Distribution of GFAP in Squamata: Extended Immunonegative Areas, Astrocytes, High Diversity, and Their Bearing on Evolution

Lőrincz

Kálmán

2020

Front. Neuroanat.

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Squamata is one of the richest and most diverse extant groups. The present study investigates the glial fibrillary acidic protein (GFAP)-immunopositive elements of five lizard and three snake species; each represents a different family. The study continues our former studies on bird, turtle, and caiman brains. Although several studies have been published on lizards, they usually only investigated one species. Almost no data are available on snakes. The animals were transcardially perfused. Immunoperoxidase reactions were performed with a mouse monoclonal anti-GFAP (Novocastra). The original radial ependymoglia is enmeshed by secondary, non-radial processes almost beyond recognition in several brain areas like in other reptiles. Astrocytes occur but only as complementary elements like in caiman but unlike in turtles, where astrocytes are absent. In most species, extended areas are free of GFAP-a meaningful difference from other reptiles. The predominance of astrocytes and the presence of areas free of GFAP immunopositivity are characteristic of birds and mammals; therefore, they must be apomorphic features of Squamata, which appeared independently from the evolution of avian glia. However, these features show a high diversity; in some lizards, they are even absent. There was no principal difference between the glial structures of snakes and lizards. In conclusion, the glial structure of Squamata seems to be the most apomorphic one among reptiles. The high diversity suggests that its evolution is still intense. The comparison of identical brain areas with different GFAP contents in different species may promote understanding the role of GFAP in neuronal networks. Our findings are in accordance with the supposal based on our previous studies that the GFAP-free areas expand during evolution.

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Section: Discussionmentioning

confidence: 99%

Distribution of GFAP in Squamata: Extended Immunonegative Areas, Astrocytes, High Diversity, and Their Bearing on Evolution

Lőrincz

Kálmán

2020

Front. Neuroanat.

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“…Fossil turtle tracks are known from the Mesozoic and Cenozoic, with some evidence that the earliest known tracks, from the Early Triassic, are older than the oldest known skeletal remains (Lichtig et al, 2018). The turtle track record covers a variable range of morphologies reflecting the locomotion of different-sized marine and freshwater turtles while either swimming or progressing on land.…”

Section: Ichnotaxonomymentioning

confidence: 99%

New fossil sea turtle trackway morphotypes from the Pleistocene of South Africa highlight role of ichnology in turtle paleobiology

et al. 2019

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More than 130 late Pleistocene trackway sites from the coastal eolianites and beach deposits of the Cape south coast, South Africa, have previously mostly yielded tracks of large mammals and birds. However, two sites east of Still Bay, and a third near Garden Route National Park, yield distinctive trackways of hatchling sea turtles, made during the short posthatching (postemergence) interval when the trackmakers headed for the sea. One assemblage of approximately parallel trackways indicates smaller loggerhead turtle hatchlings, with alternating gaits, and contrasts with a wider trackway indicating a leatherback turtle hatchling. These are the world's first reports of fossil traces that document this brief “run-for the-sea” phenomenon. They help delineate late Pleistocene sea turtle breeding ranges and indicate climatic conditions along the Cape south coast. Ichnotaxonomically defined swim tracks of large adult sea turtles are known from a few Mesozoic sites. Likewise, walking and swim traces of terrestrial freshwater turtles are also known from the Mesozoic and Cenozoic. However, as no ichnotaxonomy exists for these diagnostic hatchling trails, we assign the trackways of the inferred loggerheads to the new ichnotaxon Australochelichnus agulhasii ichnogen. et ichnosp. nov., and the inferred leatherback trackway to Marinerichnus latus ichnogen. et ichnosp. nov.

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“…However, they never show a pronounced heteropody 6 . Their tracks are always nearly in parallel rows due to the constraints imposed by the presence of the shell 17 . Besides, amphibians have pentadactyl pes with rounded tips of digits, generally without claw marks 18 .…”

Section: Resultsmentioning

confidence: 99%

The first possible choristoderan trackway from the Lower Cretaceous Daegu Formation of South Korea and its implications on choristoderan locomotion

Lee

Kong

Jung

2020

Sci Rep

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Here we report a new quadrupedal trackway found in the Lower Cretaceous Daegu Formation (Albian) in the vicinity of Ulsan Metropolitan City, South Korea, in 2018. A total of nine manus-pes imprints show a strong heteropodous quadrupedal trackway (length ratio is 1:3.36). Both manus and pes tracks are pentadactyl with claw marks. The manus prints rotate distinctly outward while the pes prints are nearly parallel to the direction of travel. The functional axis in manus and pes imprints suggests that the trackmaker moved along the medial side during the stroke progressions (entaxonic), indicating weight support on the inner side of the limbs. There is an indication of webbing between the pedal digits. These new tracks are assigned to Novapes ulsanensis, n. ichnogen., n. ichnosp., which are well-matched not only with foot skeletons and body size of Monjurosuchus but also the fossil record of choristoderes in East Asia, thereby N. ulsanensis could be made by a monjurosuchid-like choristoderan and represent the first possible choristoderan trackway from Asia. N. ulsanensis also suggests that semi-aquatic choristoderans were capable of walking semi-erect when moving on the ground with a similar locomotion pattern to that of crocodilians on land. South Korea has become globally famous for various tetrapod footprints from Cretaceous strata 1 , among which some clades such as frogs 2 , birds 3 and mammals 4 have been proved for their existences only with ichnological evidence. Recently, a new quadrupedal trackway with a pronounced heteropody (sensu stricto) 5 was discovered in the Daegu Formation (Albian, Lower Cretaceous), Ulsan City, which consists of nine manus-pes sets (Fig. 1). Both manus and pes are pentadactyl with sharp claw marks. They look different from any known quadrupedal dinosaur footprints because there is a clear indication of webbing between the pedal digits. During the Mesozoic, the webbed footprints have been occasionally reported in various quadrupedal animals such as freshwater turtles 6 , amphibians 7 , crocodyliforms 8 , and pterosaurs 9. However, new footprints differ from their tracks in morphology and appear to belong to that of other clade. Therefore, the purpose of this paper is to describe the new type of tracks and to investigate the possible trackmaker by comparing their ichnological features with skeletal ones. In addition, the trackmaker's locomotory posture on land was inferred from the trackway pattern. Results Systematic ichnology. Ichnogenus Novapes ichnogen. nov. (Figs. 2, 3). Type species. Novapes ulsanensis ichnogen. et ichnosp. nov., by monotypy and designation herein. Diagnosis. Quadrupedal tracks with a pronounced heteropody; pentadactyl manus impression with claw marks and semi-symmetrical outline, wider than longer; divergence between digit I and V imprints ranges 180° to 210°; the digit IV imprint slightly longer than digit II; entaxonic; pentadactyl pes impression with claw marks and asymmetrical outline (i.e., lateral digits are more developed), longer than wide; webbing bet...

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Triassic turtle tracks and the origin of turtles

Cited by 39 publications

References 28 publications

Distribution of GFAP in Squamata: Extended Immunonegative Areas, Astrocytes, High Diversity, and Their Bearing on Evolution

Distribution of GFAP in Squamata: Extended Immunonegative Areas, Astrocytes, High Diversity, and Their Bearing on Evolution

New fossil sea turtle trackway morphotypes from the Pleistocene of South Africa highlight role of ichnology in turtle paleobiology

The first possible choristoderan trackway from the Lower Cretaceous Daegu Formation of South Korea and its implications on choristoderan locomotion

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