scholarly journals The last surviving Thalassochelydia—A new turtle cranium from the Early Cretaceous of the Purbeck Group (Dorset, UK)

2020 ◽  
Author(s):  
Jérémy Anquetin ◽  
Charlotte André
Keyword(s):  
Phylogenetic Analysis ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Ventral View ◽  
Present Contribution ◽  
Southern England ◽  
Coastal Marine ◽  
Objective Evidence ◽  
The Moment ◽  
A New Species

Background. The mostly Berriasian (Early Cretaceous) Purbeck Group of southern England has produced a rich turtle fauna dominated by the freshwater paracryptodires Pleurosternon bullockii and Dorsetochelys typocardium. Each of these species is known by numerous relatively complete shells and by a single cranium. The two other turtles found in the Purbeck Group (Hylaeochelys belli, a species of uncertain affinities, and the terrestrial helochelydrid "Helochelydra" anglica) are known only from shell remains.Methods. In the present contribution, we describe a new turtle cranium from the Purbeck Group of Swanage, Dorset (southern England). We also explore the phylogenetic relationships of this new cranium and of Hylaeochelys belli in the context of a recently published global turtle matrix.Results. Before complete preparation, the new Purbeck cranium was provisionally referred to Dorsetochelys typocardium, but our analysis clearly contradicts a referral to this species in particular and to paracryptodires in general. In contrast, the new cranium shares a number of features with the Late Jurassic, coastal marine Thalassochelydia, including a posterolaterally open foramen palatinum posterius, a strong ridge on the posterior surface of the processus articularis of the quadrate, a strong posterior orientation of the processus articularis in ventral view, and a processus trochlearis oticum limited to the medial part of the otic chamber and bordered by a deep recess laterally. Our phylogenetic analysis confirms a placement of the new Purbeck cranium within the clade Thalassochelydia.Discussion. In terms of morphology, the new Purbeck cranium does not correspond to any known taxon. However, we refrain from naming a new species based on it because there is a good chance that this cranium actually belongs to the shell-based species Hylaeochelys belli (also recovered as a thalassochelydian in our phylogenetic analysis). Unfortunately, we lack any objective evidence to support this conclusion for the moment. In any case, the new Purbeck cranium confirms what others have previously suggested based on Hylaeochelys belli: thalassochelydian turtles survived the Jurassic-Cretaceous transition.

scholarly journals A new species of baenid turtle from the Early Cretaceous Lakota Formation of South Dakota

Fossil Record ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 1-13
Author(s):  
Walter G. Joyce ◽  
Yann Rollot ◽  
Richard L. Cifelli
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
South Dakota ◽  
Early Cretaceous ◽  
Fossil Record ◽  
Late Jurassic ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Relationship Of ◽  
A New Species

Abstract. Baenidae is a clade of paracryptodiran turtles known from the late Early Cretaceous to Eocene of North America. The proposed sister-group relationship of Baenidae to Pleurosternidae, a group of turtles known from sediments dated as early as the Late Jurassic, suggests a ghost lineage that crosses the early Early Cretaceous. We here document a new species of paracryptodiran turtle, Lakotemys australodakotensis gen. and sp. nov., from the Early Cretaceous (Berriasian to Valanginian) Lakota Formation of South Dakota based on a poorly preserved skull and two partial shells. Lakotemys australodakotensis is most readily distinguished from all other named Late Jurassic to Early Cretaceous paracryptodires by having a broad, baenid-like skull with expanded triturating surfaces and a finely textured shell with a large suprapygal I that laterally contacts peripheral X and XI and an irregularly shaped vertebral V that does not lap onto neural VIII and that forms two anterolateral processes that partially separate the vertebral IV from contacting pleural IV. A phylogenetic analysis suggests that Lakotemys australodakotensis is a baenid, thereby partially closing the previously noted gap in the fossil record.

scholarly journals Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia)

2014 ◽  
Vol 1 (2) ◽  
pp. 140222 ◽  
Author(s):  
Mark T. Young ◽  
Stéphane Hua ◽  
Lorna Steel ◽  
Davide Foffa ◽  
Stephen L. Brusatte ◽  
...  
Keyword(s):  
Late Jurassic ◽  
Total Body Length ◽  
Coastal Marine ◽  
Geological Age ◽  
Northeastern France ◽  
Total Body ◽  
Upper Kimmeridgian ◽  
A New Species ◽  
Lines Of Evidence ◽  
Lower Kimmeridgian

Machimosaurus was a large-bodied genus of teleosaurid crocodylomorph, considered to have been durophagous/chelonivorous, and which frequented coastal marine/estuarine ecosystems during the Late Jurassic. Here, we revise the genus based on previously described specimens and revise the species within this genus. We conclude that there were three European Machimosaurus species and another taxon in Ethiopia. This conclusion is based on numerous lines of evidence: craniomandibular, dental and postcranial morphologies; differences in estimated total body length; geological age; geographical distribution; and hypothetical lifestyle. We re-diagnose the type species Machimosaurus hugii and limit referred specimens to only those from Upper Kimmeridgian–Lower Tithonian of Switzerland, Portugal and Spain. We also re-diagnose Machimosaurus mosae , demonstrate that it is an available name and restrict the species to the uppermost Kimmeridgian–lowermost Tithonian of northeastern France. We re-diagnose and validate the species Machimosaurus nowackianus from Harrar, Ethiopia. Finally, we establish a new species, Machimosaurus buffetauti , for the Lower Kimmeridgian specimens of France and Germany (and possibly England and Poland). We hypothesize that Machimosaurus may have been analogous to the Pliocene–Holocene genus Crocodylus in having one large-bodied taxon suited to traversing marine barriers and additional, geographically limited taxa across its range.

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 A derived dryolestid mammal indicates possible insular endemism in the Late Jurassic of Germany

2021 ◽  
Vol 108 (3) ◽  
Author(s):  
Thomas Martin ◽  
Alexander O. Averianov ◽  
Julia A. Schultz ◽  
Achim H. Schwermann ◽  
Oliver Wings
Keyword(s):  
Phylogenetic Analysis ◽  
Early Cretaceous ◽  
Lower Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
New Taxon ◽  
Lower Saxony ◽  
Therian Mammal ◽  
Geological Age ◽  
Near Shore

AbstractThe Langenberg Quarry near Bad Harzburg has yielded the first Jurassic stem therian mammal of Germany, recovered from Kimmeridgian (Late Jurassic) near shore deposits of a palaeo-island within the Lower Saxony Basin of the European archipelago. The new stem therian is represented by one lower and three upper molars. Hercynodon germanicus gen. et sp. nov. is attributed to the Dryolestidae, a group of pretribosphenic crown mammals that was common in western Laurasia from the Middle Jurassic to the Early Cretaceous. The new taxon is characterised by small size, a reduced cusp pattern in the upper molars lacking a metacone, and enhancement of the shearing crests paracrista and metacrista. Phylogenetic analysis identified Hercynodon gen. nov. as sister taxon of Crusafontia from the Lower Cretaceous (Barremian) of Spain. Both taxa belong to an endemic European clade of dryolestids, including also Achyrodon and Phascolestes from the earliest Cretaceous (Berriasian) of England. Despite its greater geological age, Hercynodon gen. nov. is the most derived representative of that clade, indicated by the complete reduction of the metacone. The discrepancy between derived morphology and geological age may be explained by an increased rate of character evolution in insular isolation. Other insular phenomena have earlier been observed in vertebrates from the Langenberg Quarry, such as dwarfism in the small sauropod Europasaurus, and possible gigantism in the morganucodontan mammaliaform Storchodon and the pinheirodontid multituberculate mammal Teutonodon which grew unusually large.

Strepsiptera and triungula in Cretaceous amber

2005 ◽  
Vol 36 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Valerie Schawaroch ◽  
Jeyaraney Kathirithamby ◽  
David Grimaldi
Keyword(s):  
Phylogenetic Analysis ◽  
New Jersey ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Adult Male ◽  
Late Jurassic ◽  
Sister Group ◽  
Baltic Amber ◽  
Burmese Amber ◽  
The Family

AbstractThe first definitive strepsipteran is reported from the Cretaceous, named Cretostylops engeli, n.gen., n.sp., which is an adult male in amber from the mid-Cretaceous (approximately Cenomanian) of northern Myanmar (Burma). A triungulin from the Late Cretaceous (Campanian, c. 80 myo) of Manitoba, Canada is possibly a strepsipteran. The triungulin is described in detail but its morphology does not conform to any known clade of Recent strepsipterans. Other Cretaceous triungula reported here are in Burmese amber and are probably of the family Rhipiphoridae (Coleoptera), and bizarre (possibly coleopteran) triungula in mid-Cretaceous (Turonian, c. 90 myo) amber from New Jersey, USA. Phylogenetic analysis confirms the primitive position of Cretostylops among families of Strepsiptera, but it is not as primitive as Protoxenos in Eocene Baltic amber. Protoxenos and Cretostylops are still too highly modified to address the controversial relationships of Strepsiptera among insect orders, but the generalized structure of the mandible is inconsistent with the hypothesis that this order is the sister group to Diptera or closely related to Mecopterida. Phylogeny of living and Recent Strepsiptera suggests an origin of the order in the Early Cretaceous or Late Jurassic, which is also inconsistent with this order being a sister group to the much older Diptera.

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.

scholarly journals The oldest species of the genusLaeviprosopon (Decapoda: Brachyura: Prosopidae) from the Oxfordian of Poland

2020 ◽  
Vol 63 (1) ◽  
pp. 9-13
Author(s):  
Natalia Starzyk
Keyword(s):  
New Species ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Southern Poland ◽  
A New Species

Till now the genus Laeviprosopon has comprised 12 species aged from the Late Jurassic to the end of the Early Cretaceous. Recently a new species was found in the Oxfordian locality of Polish Jura Chain, Laeviprosopon musialiki n. sp., described herein. Representatives of the genus Laeviprosopon are very rare in the Oxfordian localities of southern Poland. Laeviprosopon musialiki n. sp. is the oldest member of the genus.

scholarly journals A new plesiosaurian from the Jurassic–Cretaceous transitional interval of the Slottsmøya Member (Volgian), with insights into the cranial anatomy of cryptoclidids using computed tomography

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8652 ◽  
Author(s):  
Aubrey Jane Roberts ◽  
Patrick S. Druckenmiller ◽  
Benoit Cordonnier ◽  
Lene L. Delsett ◽  
Jørn H. Hurum
Keyword(s):  
Computed Tomography ◽  
Phylogenetic Analysis ◽  
High Resolution ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
New Genus ◽  
Pectoral Girdle ◽  
High Latitudes ◽  
New Genus And Species ◽  
Major Clade

Cryptoclidids are a major clade of plesiosauromorph plesiosaurians best known from the Middle—Late Jurassic, but little is known regarding their turnover into the Early Cretaceous. Of the known cryptoclidid genera, most preserve only a limited amount of cranial material and of these Cryptoclidus eurymerus, displays the most complete, but compressed cranium. Thus, the lack of knowledge of the cranial anatomy of this group may hinder the understanding of phylogenetic interrelationships, which are currently predominantly based on postcranial data. Here we present a nearly complete adult cryptoclidid specimen (PMO 224.248) representing a new genus and species Ophthalmothule cryostea gen et sp. nov., from the latest Jurassic to earliest Cretaceous part of the Slottsmøya Member, of central Spitsbergen. The holotype material preserves a complete cranium, partial mandible, complete and articulated cervical, pectoral and anterior to middle dorsal series, along with the pectoral girdle and anterior humeri. High resolution microcomputed tomography reveals new data on the cranial anatomy of this cryptoclidid, including new internal features of the braincase and palate that are observed in other cryptoclidids. A phylogenetic analysis incorporating new characters reveals a novel tree topology for Cryptoclididae and particularly within the subfamily Colymbosaurinae. These results show that at least two cryptoclidid lineages were present in the Boreal Region during the latest Jurassic at middle to high latitudes.

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