A review of Leidyosuchus canadensis Lambe, 1907 (Archosauria: Crocodylia) and an assessment of cranial variation based upon new material

2001 ◽  
Vol 38 (12) ◽  
pp. 1665-1687 ◽  
Author(s):  
Xiao-Chun Wu ◽  
Anthony P Russell ◽  
Donald B Brinkman
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Individual Variation ◽  
The Other ◽  
Cranial Morphology ◽  
Cranial Variation ◽  
New Information ◽  
New Material ◽  
Incisive Foramen ◽  
Two Stages

Cranial morphology of Leidyosuchus canadensis Lambe 1907 is reviewed based on previously undescribed material—seven skulls and eight mandibles. This species can be distinctively diagnosed by more than 10 derived features. New information supports the contention that L. canadensis is the sole representative of Leidyosuchus, and indicates that it is very different from the other species previously assigned to this taxon. The membership of L. canadensis within Alligatoroidea is also demonstrated by new information revealed in this study. Ontogenetic and individual variation in the cranial anatomy of L. canadensis are documented. The contact of the premaxillary–maxillary suture with the incisive foramen is not diagnostic of the taxon; rather, it exhibits individual variation. Leidyosuchus is endemic to North America. There was no faunal interchange of crocodyliforms between North America and central Asia during the last two stages of the Late Cretaceous.

Cretaceous Woods from the Farafra Oasis, Egypt

IAWA Journal ◽  
2006 ◽  
Vol 27 (2) ◽  
pp. 137-143 ◽  
Author(s):  
Marwah M. Kamal El-Din ◽  
E.A Wheeler ◽  
J.A. Bartlett
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
The Other ◽  
Axial Parenchyma ◽  
Perforation Plates

There are fewer than 200 angiosperm wood records for the whole of the Cretaceous; the majority are from North America, Europe, and Asia. This paper describes two petrified woods from the Late Cretaceous Hefhuf Formation, Farafra Oasis, Egypt, a locality near the Campanian equator. Affinities of these two wood types cannot be determined with certainty. One wood has characteristics seen in the Lauraceae, Moraceae, and Anacardiaceae; the other wood has exclusively uniseriate homocellular rays, scalariform perforation plates, rare axial parenchyma, and alternate-opposite intervessel pitting.

scholarly journals Added nerineoid gastropod evidence for a warm Turonian sea in southern California

2002 ◽  
Vol 76 (2) ◽  
pp. 386-390 ◽  
Author(s):  
L. R. Saul ◽  
R. L. Squires
Keyword(s):  
North America ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Southern California ◽  
The Other ◽  
Northern California ◽  
The Pacific ◽  
Northeastern Pacific ◽  
Pacific Slope ◽  
North America North

Nerineoids, so typical of the Jurassic and Early Cretaceous in Europe, are usually rare and lacking in diversity in North America north of Mexico. This is especially true of the Pacific slope faunas. Only three species of nerineoid gastropods have previously been reported from the Cretaceous of California (Saul and Squires, 1998). The oldest of these species, Aphanoptyxis andersoni Saul and Squires, 1998, is from the Early Cretaceous (Hauterivian) in northern California. The other two species are Late Cretaceous (Turonian): Aphanoptyxis californica Saul and Squires, 1998, is from northern California, and Nerinella santana Saul and Squires, 1998, is from a locality and strata in southern California near the occurrence of Nerinella califae n. sp. The description of N. califae n. sp. gives California the greatest diversity of Turonian northeastern Pacific slope nerineoids, namely, Aphanoptyxis californica and two species of Nerinella. These Turonian nerineoids are also, thus far, the geologically youngest North American Pacific slope nerineoids.

New material of Gilmoremys lancensis nov. comb. (Testudines: Trionychidae) from the Hell Creek Formation and the diagnosis of plastomenid turtles

2011 ◽  
Vol 85 (3) ◽  
pp. 442-459 ◽  
Author(s):  
Walter G. Joyce ◽  
Tyler R. Lyson
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
North Dakota ◽  
Late Cretaceous ◽  
Hell Creek Formation ◽  
Secondary Palate ◽  
New Material

Plastomenidae is a poorly diagnosed clade of extinct soft-shelled turtles (Trionychidae) known from the Campanian to Eocene of North America. Five skulls, a mandible, two carapaces, and numerous plastral remains from the Hell Creek Formation (Late Cretaceous, Maastrichtian) of North Dakota and Montana are referable to Gilmoremys lancensis nov. comb., a taxon previously known from a carapace and xiphiplastron only. Gilmoremys lancensis is diagnosed by a carapace that is covered by elongate sinusoidal grooves, distally expanded second costals, hyoplastral shoulders, an extensive secondary palate with accessory ridges, an extremely elongate mandible, a contribution of the parietal to the wall of the orbit, and a posterior ossified narial canal. A phylogenetic analysis of all well-known plastomenid turtles establishes Gilmoremys lancensis as the most basal known plastomenid and reveals that cranial characters are more reliable in diagnosing plastomenid turtles, in particular the contribution of the parietal to the orbit wall and the extensive secondary palate. All plastomenid turtles with a locked entoplastron are placed in Hutchemys. Assuming that all taxa are monophyletic, the phylogenetic analysis implies that the G. lancensis lineage is the only one to go extinct at the K/T boundary, whereas the four remaining plastomenid lineages survive. Extensive ghost ranges are nevertheless apparent. Taphonomic considerations indicate that G. lancensis was a riverine turtle, whereas more derived plastomenids preferred swampy habitats.

Cranial Morphology ofTheriosuchus sympiestodon(Mesoeucrocodylia, Atoposauridae) and the Widespread Occurrence ofTheriosuchusin the Late Cretaceous of Europe

2014 ◽  
Vol 88 (3) ◽  
pp. 444-456 ◽  
Author(s):  
Jeremy E. Martin ◽  
Márton Rabi ◽  
Zoltán Csiki-Sava ◽  
Ştefan Vasile
Keyword(s):  
Late Cretaceous ◽  
Cranial Morphology ◽  
Morphological Description ◽  
Ontogenetic Variation ◽  
General Area ◽  
Widespread Occurrence ◽  
Widespread Distribution ◽  
New Material ◽  
Haţeg Basin

We present a detailed morphological description of the type-locality cranial material ofTheriosuchus sympiestodonMartin, Rabi, and Csiki, 2010 from the Maastrichtian Densuş-Ciula Formation of the Haţeg Basin, Romania together with new material of isolated cranial elements and teeth from various sites of the same general area. The recognition of several individuals of distinct sizes allows for an assessment of ontogenetic variation in this taxon. New material, consisting of isolated teeth and an incomplete maxilla with in situ teeth, coming from various late Campanian/early Maastrichtian sites in southern France is referable to ?Theriosuchussp. and hints to a rare but widespread distribution ofTheriosuchusin the Late Cretaceous European archipelago.

A new Late Cretaceous (Turonian) basal euteleostean fish from Lac des Bois of the Northwest Territories of Canada

2002 ◽  
Vol 39 (11) ◽  
pp. 1579-1590 ◽  
Author(s):  
Christopher Fielitz
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Late Cretaceous ◽  
New Genus ◽  
The Other ◽  
Neural Spine ◽  
New Genus And Species ◽  
Caudal Fin ◽  
Sensory Canal ◽  
High Degree

A new genus and species of Late Cretaceous euteleost, Avitosmerus canadensis, is described from an assemblage of fossil fishes found in a Late Cretaceous (Turonian) unnamed member (unit E) of the Great Bear Basin from Lac des Bois, Northwest Territories, Canada. It is a small fusiform fish characterized by a long slender supraorbital, the presence of a small suprapreopercle, branches of the preopercular sensory canal that reach the edge of the preopercle, and an anterior supraneural that is twice as large as those posterior to it. Additionally, elements of its caudal fin show a high degree of fusion. Avitosmerus is one of ten described Cretaceous basal euteleosts that are found worldwide (Avitosmerus, Barcarenichthys, Erichalcis, Gaudryella, Gharbouria, Humbertia, Kermichthys, Manchurichthys, Paravinciguerria, and Stompooria). Avitosmerus and Erichalcis are the only two basal euteleosts that have been described from the Cretaceous of North America. Placement of Avitosmerus into the Euteleostei is based on the presence of a free stegural, and the large first supraneural. Both of these characters are somewhat controversial and are in need of reexamination. Avitosmerus shares a number of characters with the other Cretaceous basal euteleosts, as well as Recent basal euteleosts, including a separate rostrodermethmoid and mesethmoid (Gaudryella, Erichalcis, Gharbouria, the Osmeridae, and the Coregonidae), lobate condyles of the hyomandibula (Avitosmerus, Gaudryella, and Gharbouria), leaf-shaped neural spine on the first preural centrum (Kermichthys), and the fusion of the parhypural, first, and second hypurals (Gaudryella).

scholarly journals A new microvertebrate assemblage from the Mussentuchit Member, Cedar Mountain Formation: insights into the paleobiodiversity and paleobiogeography of early Late Cretaceous ecosystems in western North America

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5883 ◽  
Author(s):  
Haviv M. Avrahami ◽  
Terry A. Gates ◽  
Andrew B. Heckert ◽  
Peter J. Makovicky ◽  
Lindsay E. Zanno
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Western North America ◽  
Western Interior Seaway ◽  
Cedar Mountain Formation ◽  
New Information ◽  
Asian Clade ◽  
Quantitative Analyses ◽  
Dinosaur Teeth ◽  
Early Late

The vertebrate fauna of the Late Cretaceous Mussentuchit Member of the Cedar Mountain Formation has been studied for nearly three decades, yet the fossil-rich unit continues to produce new information about life in western North America approximately 97 million years ago. Here we report on the composition of the Cliffs of Insanity (COI) microvertebrate locality, a newly sampled site containing perhaps one of the densest concentrations of microvertebrate fossils yet discovered in the Mussentuchit Member. The COI locality preserves osteichthyan, lissamphibian, testudinatan, mesoeucrocodylian, dinosaurian, metatherian, and trace fossil remains and is among the most taxonomically rich microvertebrate localities in the Mussentuchit Member. To better refine taxonomic identifications of isolated theropod dinosaur teeth, we used quantitative analyses of taxonomically comprehensive databases of theropod tooth measurements, adding new data on theropod tooth morphodiversity in this poorly understood interval. We further provide the first descriptions of tyrannosauroid premaxillary teeth and document the earliest North American record of adocid remains, extending the appearance of this ancestrally Asian clade by 5 million years in western North America and supporting studies of pre-Cenomaninan Laurasian faunal exchange across Beringia. The overabundance of mesoeucrocodylian remains at the COI locality produces a comparatively low measure of relative biodiversity when compared to other microvertebrate sites in the Mussentuchit Member using both raw and subsampling methods. Much more microvertebrate research is necessary to understand the roles of changing ecology and taphonomy that may be linked to transgression of the Western Interior Seaway or microhabitat variation.

scholarly journals New trionychoid specimens and turtle fauna from the Lower Cretaceous Kitadani Formation of the Tetori Group in central Japan

2015 ◽  
Author(s):  
Teppei Sonoda ◽  
Yoichi Azuma ◽  
Ren Hirayama ◽  
Hisao Ando
Keyword(s):  
North America ◽  
East Asia ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Early Evolution ◽  
Central Japan ◽  
New Information ◽  
Fossil Records ◽  
Shell Fragments ◽  
Shed Light

Background. The Trionychoidea were dominant turtles in the Late Cretaceous of Asia and North America. Although Early Cretaceous trionychoids are quite important to reveal their origin and the early evolution, their fossil records are very poor so far. The Lower Cretaceous Kitadani Formation of the Tetori Group is one of the most productive dinosaur-bearing beds of Japan, and has yielded a lot of turtle remains. Trionychid, adocid, and nanhsiungchelyid were published as the oldest records by Hirayama (2002). Herein, we report new information about trionychid and adocid turtles from the Kitadani Formation. Methods. We examined and morphologically described more than 700 materials (mostly isolated shell fragments) from the Kitadani Formation (late Barremian to Aptian) of the Tetori Group in Katsuyama City, Fukui Prefecture, central Japan. All specimens have been collected in the paleontological excavations by Fukui Prefectural Dinosaur Museum since 1988. Results. The turtle fauna consists of four trionychoid taxa and two other eucryptodires. About 80 % are assigned to the Trionychoidea including a trionychid, two taxa of adocids, and a nanhsiungchelyid. Shell and skeletal assemblages of a soft-shelled turtle (FPDM-V9487, 9489) were newly discovered. These have the following synapomorphies as the Trionychidae; vermiculated shell sculpturing, loss of scale sulci, lack of peripheral bones, reduction of plastron, no osseous bridge between carapace and plastron. Furthermore, a reduction of eighth costal, and an indistinct sculpture and callosity on the hypoplastron are common characters in Perochelys, Gobiapalone, and Apalonina. The Adocidae, an extinct semi-aquatic turtle, is the most dominant among turtles in this locality and is composed of two different taxa. Nearly complete shell materials of Adocus sp. have been recovered based on hundreds of fragmentary shell materials and the newly collected shell assemblage of one individual (FPDM-V9173). Another adocid, gen. et sp. indet., is newly recognized on the basis of costals, peripherals, and a hypoplastron. This adocid is distinguished from Adocus sp. by the possession of the marginal scales limited within peripherals, and thinner shells. Discussion. Trionychoids from the Kitadani Formation were composed of dominant families in the Late Cretaceous of Asia and North America. Trionychoids from underlying Kuwajima and Akaiwa formations (Hauterivian to Barremian) of the Tetori Group are quite different. More primitive trionychoids such as “Trionychoidea indet.” and Kappachelys okurai have been unearthed from these formations. This stratigraphical succession suggests that morphological and paleoecological diversification among trionychoid turtles began during the Barremian or Aptian in East Asia. Fossil turtles from the Tetori Group could shed light on the early evolution of trionychoid families.

A new record of the pliosaurBrachauchenius lucasiWilliston, 1903 (Reptilia: Sauropterygia) of Turonian (Late Cretaceous) age, Morocco

2015 ◽  
Vol 153 (3) ◽  
pp. 449-459 ◽  
Author(s):  
D. ANGST ◽  
N. BARDET
Keyword(s):  
North America ◽  
South America ◽  
Late Cretaceous ◽  
North Africa ◽  
New Record ◽  
The Other ◽  
Western Interior Seaway ◽  
Marine Fauna ◽  
Marine Reptiles ◽  
Northern South America

AbstractThe site of Goulmima (south Morocco) is well known for its rich marine fauna of Turonian age (Late Cretaceous). It has yielded a large variety of invertebrates but also of vertebrate taxa, represented by actinopterygians and marine reptiles including Plesiosauria (Sauropterygia) and Mosasauroidea (Squamata). The Plesiosauria are known so far by two major clades of Plesiosauroidea: the Elasmosauridae (Libonectes atlasenseBuchy, 2005) and the Polycotylidae (Thililua longicollis, Bardet, Suberbiola & Jalil, 2003a;Manemergus angirostrisBuchy, Metayer & Frey, 2005). Here we describe a new specimen of plesiosaur found in the same outcrop, differing from those previously cited and belonging to the other large plesiosaur clade, the Pliosauroidea. Comparison of this specimen with other Plesiosauria shows that it belongs toBrachauchenius lucasiWilliston (1903), a species previously known only from the Cenomanian–Turonian stages of the Western Interior Seaway of North America and in the upper Barremian succession of northern South America (Colombia). The description of this species on a contemporaneous site of North Africa significantly expands its palaeobiogeographic distribution. This discovery confirms the affinities between marine faunas of the Western Interior Seaway and those of North Africa at this time, and also permits a better understanding of the palaeobiology of the Goulmima outcrop. A discussion about the systematical status ofPolyptychodonOwen, 1841 is also provided.

A large pteranodontid pterosaur from the Late Cretaceous of Eastern Europe

2020 ◽  
pp. 1-13
Author(s):  
Alexander O Averianov ◽  
Maxim S Arkhangelsky
Keyword(s):  
North America ◽  
Eastern Europe ◽  
Late Cretaceous ◽  
Upper Cretaceous ◽  
The Other

Abstract The Campanian Beloe Ozero locality within the Rybushka Formation in Saratov Province, Russia, is one of the richest and most diverse Upper Cretaceous pterosaur localities in Europe. It produces identifiable remains of Pteranodontidae indet. and Azhdarchidae indet., as well as bones which can be attributed to either of these groups. The pteranodontid specimens from the Beloe Ozero locality described in this paper include a cervical III, distal scapula, humerus deltopectoral crest, proximal syncarpal, preaxial carpal and complete femur. Based on the femur and proximal syncarpal, the wingspan estimate for the Beloe Ozero pteranodontid varies from 5.2 to 6.5 m. Volgadraco bogolubovi, known from the neighbouring Shyrokii Karamysh locality of the same formation and attributed previously to the Azhdarchidae, is more likely pteranodontid than azhdarchid. The other putative records of the Pteranodontidae in the Late Cretaceous of North America, Europe and Asia are discussed. Pteranodontid pterosaurs had a much wider distribution on the northern continents in the Late Cretaceous than previously thought.

scholarly journals New information on two Late Cretaceous (Turonian) fishes from Lac des Bois, Northwest Territories, Canada

2015 ◽  
Vol 1 ◽  
pp. 23 ◽  
Author(s):  
Alison M Murray ◽  
Stephen L Cumbaa
Keyword(s):  
Northwest Territories ◽  
Late Cretaceous ◽  
New Information ◽  
New Material

Fishes from Turonian deposits at Lac des Bois, Northwest Territories, Canada, have previously been described based on material from calcareous mudstone concretions collected in 1969. A more recent collecting trip to the locality in 2010 led to the discovery of fossil fishes in a shale layer. These fishes, preserved in a different manner from the earlier collections, provide new information and allow reinterpretations on two previously described fishes, Aquilopiscis wilsoni (Pachyrhizodontidae) and Avitosmerus canadensis (Euteleostei). Although the new material allows a better understanding of these two fishes, it does not change our ideas about their relationships. Avitosmerus canadensis remains in the Euteleostei with relationships uncertain, and Aquilopiscis wilsoni is confirmed as a member of the Pachyrhizodontidae.

Sign in / Sign up

Export Citation Format

Share Document