scholarly journals Peer Review #2 of "The comparative osteology of Plesiochelys bigleri n. sp., a new coastal marine turtle from the Late Jurassic of Porrentruy (Switzerland) (v0.1)"

2017 ◽  
Author(s):  
M Rabi
Keyword(s):  
Peer Review ◽  
Late Jurassic ◽  
Marine Turtle ◽  
Coastal Marine ◽  
Comparative Osteology

scholarly journals The comparative osteology of Plesiochelys bigleri n. sp., a new coastal marine turtle from the Late Jurassic of Porrentruy (Switzerland)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3482 ◽  
Author(s):  
Christian Püntener ◽  
Jérémy Anquetin ◽  
Jean-Paul Billon-Bruyat
Keyword(s):  
Late Jurassic ◽  
Western Europe ◽  
Marine Turtle ◽  
Appendicular Skeleton ◽  
Crown Group ◽  
Coastal Marine ◽  
Coastal Marine Ecosystems ◽  
Swiss Jura ◽  
Nw Switzerland ◽  
Comparative Osteology

Background During the Late Jurassic, several groups of eucryptodiran turtles inhabited the shallow epicontinental seas of Western Europe. Plesiochelyidae are an important part of this first radiation of crown-group turtles into coastal marine ecosystems. Fossils of Plesiochelyidae occur in many European localities, and are especially abundant in the Kimmeridgian layers of the Swiss Jura Mountains (Solothurn and Porrentruy). In the mid-19th century, the quarries of Solothurn (NW Switzerland) already provided a large amount of fossil turtles, most notably Plesiochelys etalloni, the best-known plesiochelyid species. Recent excavations in the Porrentruy area (NW Switzerland) revealed new fossils of Plesiochelys, including numerous well-preserved shells with associated cranial and postcranial material. Methods/results Out of 80 shells referred to Plesiochelys, 41 are assigned to a new species, Plesiochelys bigleri n. sp., including a skull–shell association. We furthermore refer 15 shells to Plesiochelys etalloni, and 24 shells to Plesiochelys sp. Anatomical comparisons show that Plesiochelys bigleri can clearly be differentiated from Plesiochelys etalloni by cranial features. The shell anatomy and the appendicular skeleton of Plesiochelys bigleri and Plesiochelys etalloni are very similar. However, a statistical analysis demonstrates that the thickness of neural bones allows to separate the two species based on incomplete material. This study furthermore illustrates the extent of intraspecific variation in the shell anatomy of Plesiochelys bigleri and Plesiochelys etalloni.

scholarly journals Under the feet of sauropods: a trampled coastal marine turtle from the Late Jurassic of Switzerland?

2019 ◽  
Vol 112 (2-3) ◽  
pp. 507-515 ◽  
Author(s):  
Christian Püntener ◽  
Jean-Paul Billon-Bruyat ◽  
Daniel Marty ◽  
Géraldine Paratte
Keyword(s):  
Late Jurassic ◽  
Marine Turtle ◽  
Coastal Marine

scholarly journals A new species of the large-headed coastal marine turtle Solnhofia (Testudinata, Thalassochelydia) from the Late Jurassic of NW Switzerland

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9931
Author(s):  
Jérémy Anquetin ◽  
Christian Püntener
Keyword(s):  
New Species ◽  
Late Jurassic ◽  
Ventral View ◽  
Dorsal Surface ◽  
Marine Turtle ◽  
Close Relative ◽  
Coastal Marine ◽  
Large Head ◽  
New Material ◽  
Nw Switzerland

Background The large-headed turtle Solnhofia parsonsi is known by a handful of specimens from the Late Jurassic of Germany and Switzerland (maybe also France). Solnhofia parsonsi is traditionally regarded as a “eurysternid” Thalassochelydia, a group of small to medium sized, mostly lagoonal or marginal turtles found almost exclusively in the Late Jurassic of Europe. More recently, Solnhofia parsonsi has been proposed to be a close relative of Sandownidae, an enigmatic group of Cretaceous to Paleogene turtles characterized by a derived cranial anatomy and a wider geographical distribution. Sandownids may therefore have evolved from thalassochelydian ancestors such as Solnhofia parsonsi. Methods We herein describe new material of Solnhofia from the Kimmeridgian (Late Jurassic) of Porrentruy, NW Switzerland. The bulk of the material consists of an association of a cranium and over 180 shell bones found together in a block of marly limestone. A second cranium and a mandible from slightly younger, but nearby localities are also described. Results We refer the new material to Solnhofia brachyrhyncha n. sp. The new species shares with Solnhofia parsonsi a relatively large head, an extensive secondary palate formed primarily by the maxillae, a greatly developed processus trochlearis oticum with a contribution from the parietal and quadratojugal, a large jugal-palatine contact in the floor of the fossa orbitalis, and a posteromedial process of the jugal running on the dorsal surface of the maxilla and pterygoid. Some of these characteristics are also present in sandownids, but our morphological study clearly shows that Solnhofia brachyrhyncha is closer to Solnhofia parsonsi than to any sandownids. Discussion Solnhofia brachyrhyncha differs from Solnhofia parsonsi in many aspects, notably: a shortened and broader cranium, a shorter and posteriorly broader upper triturating surface with a slightly sinusoidal lateral margin and without contribution from the palatine, a processus trochlearis oticum more oblique in dorsal or ventral view and less concave in anterior view, choanae that do not extend posteriorly on the pterygoids, a more developed processus pterygoideus externus, a condylus mandibularis situated anterior to the level of the occipital plane, a greater ventral exposure of the parabasisphenoid, a mandible about as wide as long, a relatively short symphysis, a lower triturating surface widened posterolaterally thanks to the presence of large laterally projecting dentary tubercles, a stouter and shorter coronoid process, a splenial positioned more anteriorly along the mandibular ramus, costo-peripheral fontanelles extending more anteriorly and posteriorly along the costal series, and an escutcheon shaped central plastral fontanelle formed mostly by the hypoplastra. In addition to the morphology of the new species, we also briefly discuss about observable ontogenetic variations and possible taphonomic origin of the assemblage.

scholarly journals Under the feet of sauropods: A trampled coastal marine turtle from the Late Jurassic of Switzerland?

2019 ◽  
Author(s):  
Christian Püntener ◽  
Jean-Paul Billon-Bruyant ◽  
Daniel Marty ◽  
Géraldine Paratte
Keyword(s):  
Tidal Flat ◽  
Late Jurassic ◽  
The State ◽  
Marine Turtle ◽  
Jura Mountains ◽  
Turtle Shell ◽  
Coastal Marine ◽  
Swiss Jura

Recent excavations from the “Paléontologie A16” project brought to light thousands of dinosaur footprints and numer-ous turtle remains from the Late Jurassic of Porrentruy (Swiss Jura Mountains). While most fossil turtles (Thalassochelydia) were found in marly layers that were deposited in a coastal marine paleoenvironment, the dinosaur (theropods and sauropods) tracks were found in laminites that were deposited in a tidal flat environment. Despite extensive explo-ration, very few fossils were found in these dinosaur track-bearing laminites. On one occasion, a sub-complete turtle shell (Plesiochelys bigleri) was discovered within the laminites, embedded just beneath an important sauropod track level. The state of preservation of this specimen suggests that the turtle died on the tidal flat and was quickly buried. This is the first evidence that these turtles occasionally visited tidal flat paleoenvironments. Moreover, the particular configuration of the fossil turtle suggests that the shell was possibly trodden on by a large sauropod dinosaur.

scholarly journals Thalassemys bruntrutanan. sp., a new coastal marine turtle from the Late Jurassic of Porrentruy (Switzerland), and the paleobiogeography of the Thalassemydidae

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1282 ◽  
Author(s):  
Christian Püntener ◽  
Jérémy Anquetin ◽  
Jean-Paul Billon-Bruyat
Keyword(s):  
Late Jurassic ◽  
Marine Turtle ◽  
Jura Mountains ◽  
Marine Turtles ◽  
The Past ◽  
Coastal Marine ◽  
New Material ◽  
Swiss Jura ◽  
Nw Switzerland ◽  
A New Species

Background.The Swiss Jura Mountains are a key region for Late Jurassic eucryptodiran turtles. Already in the mid 19th century, the Solothurn Turtle Limestone (Solothurn, NW Switzerland) yielded a great amount of Kimmeridgian turtles that are traditionally referred to Plesiochelyidae, Thalassemydidae, and Eurysternidae. In the past few years, fossils of these coastal marine turtles were also abundantly discovered in the Kimmeridgian of the Porrentruy region (NW Switzerland). These findings include numerous sub-complete shells, out of which we present two new specimens ofThalassemys(Thalassemydidae) in this study.Methods.We compare the new material from Porrentruy to the type speciesTh. hugii, which is based on a well preserved specimen from the Solothurn Turtle Limestone (Solothurn, Switzerland). In order to improve our understanding of the paleogeographic distribution ofThalassemys, anatomical comparisons are extended toThalassemysremains from other European countries, notably Germany and England.Results.While one of the twoThalassemysspecimens from Porrentruy can be attributed toTh. hugii, the other specimen represents a new species,Th. bruntrutanan. sp. It differs fromTh. hugiiby several features: more elongated nuchal that strongly thickens anterolaterally; wider vertebral scales; proportionally longer plastron; broader and less inclined xiphiplastron; wider angle between scapular process and acromion process. Our results show thatTh. hugiiandTh. bruntrutanaalso occur simultaneously in the Kimmeridgian of Solothurn as well as in the Kimmeridgian of England (Kimmeridge Clay). This study is an important step towards a better understanding of the paleobiogeographic distribution of Late Jurassic turtles in Europe.

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