scholarly journals An enigmatic specialized new eutherian mammal from the Late Cretaceous of Western Europe (Northern Pyrenees)

2021 ◽  
Author(s):  
Emmanuel GHEERBRANT ◽  
Dominique TEODORI
Keyword(s):  
Phylogenetic Analysis ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Western Europe ◽  
Eutherian Mammal ◽  
Additional Material ◽  
Weak Support ◽  
Lower Jaw ◽  
Early Specialization

We report the discovery of a new Late Cretaceous eutherian mammal, Azilestes ragei n. gen., n. sp. from the Mas-d’Azil northern Pyrenean site (France), which is among the largest known. It is only known from a broken lower jaw found in uppermost levels of the Grès de Labarre Formation (early Maastrichtian). Despite its poor preservation, it displays distinctive specialized features with respect to known Cretaceous eutherians. This includes a reduced premolar formula and shortened and robust jaw, an incipient hypolophid, and a cingular-like postcristid and hypoconulid. The phylogenetic analysis suggests indeed a possible stem relationship between Azilestes n. gen. and some clades of herbivorous Cenozoic placentals, but with weak support. Several molar features reminiscent of the Zhelestidae, especially Valentinella Tabuce, Vianey-Liaud & Garcia, 2004, support instead that Azilestes n. gen. is a basal eutherian showing early specialization in a herbivorous diet convergent with some crown placentals. Whatever the suprageneric position of Azilestes n. gen., which remains to be clarified with additional material, its discovery highlights a significant diversity of European Cretaceous eutherians in contrast to their very poor fossil record.

scholarly journals A tyrannosauroid metatarsus from the Merchantville formation of Delaware increases the diversity of non-tyrannosaurid tyrannosauroids on Appalachia

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4123 ◽  
Author(s):  
Chase D. Brownstein
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Morphological Features ◽  
The West ◽  
Intermediate Grade

During the Late Cretaceous, the continent of North America was divided into two sections: Laramidia in the west and Appalachia in the east. Although the sediments of Appalachia recorded only a sparse fossil record of dinosaurs, the dinosaur faunas of this landmass were different in composition from those of Laramidia. Represented by at least two taxa (Appalachiosaurus montgomeriensis and Dryptosaurus aquilunguis), partial and fragmentary skeletons, and isolated bones, the non-tyrannosaurid tyrannosauroids of the landmass have attracted some attention. Unfortunately, these eastern tyrants are poorly known compared to their western contemporaries. Here, one specimen, the partial metatarsus of a tyrannosauroid from the Campanian Merchantville Formation of Delaware, is described in detail. The specimen can be distinguished from A. montgomeriensis and D. aquilunguis by several morphological features. As such, the specimen represents a potentially previously unrecognized taxon of tyrannosauroid from Appalachia, increasing the diversity of the clade on the landmass. Phylogenetic analysis and the morphology of the bones suggest the Merchantville specimen is a tyrannosauroid of “intermediate” grade, thus supporting the notion that Appalachia was a refugium for relict dinosaur clades.

scholarly journals A new sphenodontian (Lepidosauria: Rhynchocephalia) from the Late Triassic of Argentina and the early origin of the herbivore opisthodontians

2013 ◽  
Vol 280 (1772) ◽  
pp. 20132057 ◽  
Author(s):  
Ricardo N. Martínez ◽  
Cecilia Apaldetti ◽  
Carina E. Colombi ◽  
Angel Praderio ◽  
Eliana Fernandez ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
South America ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Late Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
Northwestern Argentina ◽  
Successful Group ◽  
Early Origin

Sphenodontians were a successful group of rhynchocephalian reptiles that dominated the fossil record of Lepidosauria during the Triassic and Jurassic. Although evidence of extinction is seen at the end of the Laurasian Early Cretaceous, they appeared to remain numerically abundant in South America until the end of the period. Most of the known Late Cretaceous record in South America is composed of opisthodontians, the herbivorous branch of Sphenodontia, whose oldest members were until recently reported to be from the Kimmeridgian–Tithonian (Late Jurassic). Here, we report a new sphenodontian, Sphenotitan leyesi gen. et sp. nov., collected from the Upper Triassic Quebrada del Barro Formation of northwestern Argentina. Phylogenetic analysis identifies Sphenotitan as a basal member of Opisthodontia, extending the known record of opisthodontians and the origin of herbivory in this group by 50 Myr.

scholarly journals The first iguanian lizard from the Mesozoic of Africa

2016 ◽  
Vol 3 (9) ◽  
pp. 160462 ◽  
Author(s):  
Sebastián Apesteguía ◽  
Juan D. Daza ◽  
Tiago R. Simões ◽  
Jean Claude Rage
Keyword(s):  
New Species ◽  
Bayesian Inference ◽  
Late Cretaceous ◽  
Fossil Record ◽  
New Taxon ◽  
Biogeographic History ◽  
Lower Jaw ◽  
Tree Inference ◽  
Inference Methods ◽  
Multiple Tree

The fossil record shows that iguanian lizards were widely distributed during the Late Cretaceous. However, the biogeographic history and early evolution of one of its most diverse and peculiar clades (acrodontans) remain poorly known. Here, we present the first Mesozoic acrodontan from Africa, which also represents the oldest iguanian lizard from that continent. The new taxon comes from the Kem Kem Beds in Morocco (Cenomanian, Late Cretaceous) and is based on a partial lower jaw. The new taxon presents a number of features that are found only among acrodontan lizards and shares greatest similarities with uromastycines, specifically. In a combined evidence phylogenetic dataset comprehensive of all major acrodontan lineages using multiple tree inference methods (traditional and implied weighting maximum-parsimony, and Bayesian inference), we found support for the placement of the new species within uromastycines, along with Gueragama sulamericana (Late Cretaceous of Brazil). The new fossil supports the previously hypothesized widespread geographical distribution of acrodontans in Gondwana during the Mesozoic. Additionally, it provides the first fossil evidence of uromastycines in the Cretaceous, and the ancestry of acrodontan iguanians in Africa.

scholarly journals Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography

2018 ◽  
Author(s):  
Anna V. Koromyslova ◽  
Paul D. Taylor ◽  
Silviu O. Martha ◽  
Matthew Riley
Keyword(s):  
New Species ◽  
Eastern Europe ◽  
Central Asia ◽  
Late Cretaceous ◽  
Western Europe ◽  
Taxonomic Revision ◽  
Published Data ◽  
Additional Material

Species commonly assigned to the cheilostome bryozoan genus Onychocella Jullien, 1882 are numerous in deposits of Late Cretaceous age. Among these are 15 species with wide stratigraphical and geographical distributions that are better placed in the genus Rhagasostoma Koschinsky, 1885. These are used here to show similarities between Late Cretaceous bryozoan associations from Western Europe and Central Asia. Type and additional material was examined of several species from the Turonian to the Maastrichtian of Western Europe, including material studied by R.M. Brydone, E. Voigt and T.A. Favorskaya and undescribed material from the Campanian and Maastrichtian of several localities in Eastern Europe and Central Asia. The new species Rhagasostoma brydonei sp. nov., R. aralense sp. nov. and R. operculatum sp. nov. are introduced. New and published data on the morphology and the stratigraphical and geographical distributions of R. inelegans (Lonsdale, 1850), R. gibbosum (Marsson, 1887), R. gibbosulum Brydone, 1936, R. rowei (Brydone, 1906) and R. mimosa (Brydone, 1930) is presented.

Zooid morphology and molecular phylogeny of the graptolite Rhabdopleura annulata (Hemichordata, Pterobranchia) from Heron Island, Australia

2020 ◽  
Vol 98 (12) ◽  
pp. 844-849
Author(s):  
Greta M. Ramírez-Guerrero ◽  
Kevin M. Kocot ◽  
Christopher B. Cameron
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Molecular Phylogenetics ◽  
The Body ◽  
Single Pair ◽  
Weak Support ◽  
Cephalic Shield ◽  
Shed Light ◽  
Rrna Sequences ◽  
16S Rrna Sequences

Rhabdopleura Allman, 1869 is one of the longest surviving animal genera. The five-known species are the only living Graptolithina, a group well known from their diverse Paleozoic fossil record. Here we add information on the soft-bodied zooids and molecular phylogenetics of Rhabdopleura annulata Norman, 1921, which was previously only known from its tubes. Tubes and zooids were collected from Heron Island, Queensland, Australia. Zooids have a single pair of tentaculated arms. Dark pigment granules are found throughout the body, and particularly dense in the pair of arms and the anterior lip of the cephalic shield. Colonies grow encrusted in and on coral debris. The tubes are either creeping or erect, but no stolon has been found. Inside of the coral matrix lacunae, the tube cortex formed a parchment-like wallpaper. Phylogenetic analysis based on combined 18S+16S rRNA sequences placed R. annulata as sister to the remaining rhabdopleurids, albeit with weak support. The biogeographic range of R. annulata extends from Indonesia to Tasmania, and New Zealand. Its occurrence on Heron Island does not extend this range, but highlights that rhabdopleurids may be more common, and in shallower waters, than previously appreciated, permitting further studies that may shed light on graptolite paleobiology.

scholarly journals Prootic anatomy of a juvenile tyrannosauroid from New Jersey and its implications for the morphology and evolution of the tyrannosauroid braincase

2018 ◽  
Author(s):  
Chase D Brownstein
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Northern Hemisphere ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Fossil Record ◽  
Atlantic Coastal Plain ◽  
Western Interior Seaway ◽  
Large Predator ◽  
Atlantic Coastal

Among the most recognizable theropods are the tyrannosauroids, a group of small to large carnivorous coelurosaurian dinosaurs that inhabited the majority of the northern hemisphere during the Cretaceous and came to dominate large predator niches in North American and Asian ecosystems by the end of the Mesozoic era. The clade is among the best-represented of dinosaur groups in the notoriously sparse fossil record of Appalachia, the Late Cretaceous landmass that occupied the eastern portion of North America after its formation from the transgression of the Western Interior Seaway. Here, the prootic of a juvenile tyrannosauroid collected from the middle-late Campanian Marshalltown Formation of the Atlantic Coastal Plain is described, remarkable for being the first concrete evidence of juvenile theropods in that plain during the time of the existence of Appalachia and the only portion of theropod braincase known from the landmass. Phylogenetic analysis recovers the specimen as an “intermediate” tyrannosauroid of similar grade to Dryptosaurus and Appalachiosaurus. Comparisons with the corresponding portions of other tyrannosauroid braincases suggest that the Ellisdale prootic is more similar to Turonian forms in morphology than to the derived tyrannosaurids of the Late Cretaceous, thus supporting the hypothesis that Appalachian tyrannosauroids and other vertebrates were relict forms surviving in isolation from their derived counterparts in Eurasia.

Blasisaurus canudoi gen. et sp. nov., a new lambeosaurine dinosaur (Hadrosauridae) from the Latest Cretaceous of Arén (Huesca, Spain)

2010 ◽  
Vol 47 (12) ◽  
pp. 1507-1517 ◽  
Author(s):  
Penelope Cruzado-Caballero ◽  
Xabier Pereda-Suberbiola ◽  
J. Ignacio Ruiz-Omeñaca
Keyword(s):  
Phylogenetic Analysis ◽  
Late Cretaceous ◽  
Junior Synonym ◽  
Posterior Process ◽  
South Central ◽  
Lower Jaw ◽  
Dorsal Edge ◽  
Dispersal Events ◽  
Central Pyrenees

Blasisaurus canudoi gen. et sp. nov. is described on the basis of disarticulated skull and lower jaw remains found in the Blasi 1 locality of Arén (Huesca, south-central Pyrenees of Spain), located in the upper part of the Arén Formation, late Maastrichtian in age. This new lambeosaurine hadrosaurid is characterized by a jugal combining a hook-like dorsal edge of the posterior process and a narrow, D-shaped infratemporal fenestra. Blasisaurus differs from Arenysaurus from the Blasi 3 site of Arén mainly by the absence of secondary ridges in the dentary teeth, and from Koutalisaurus (probably a junior synonym of Pararhabdodon ) from the Isona region of Lleida by the anteriormost portion of the dentary that is modestly deflected ventrally. A phylogenetic analysis places Blasisaurus as closely related to Arenysaurus in a clade of basal lambeosaurines more derived than Tsintaosaurus and Jaxartosaurus ; this clade forms part of a polytomy with Amurosaurus and with more derived lambeosaurines. Palaeobiogeographically, the presence of Blasisaurus and other hadrosaurids in the Maastrichtian European archipelago suggests one or, more probably, a series of dispersal events from Asia across intermittent land bridges during the second half of the Late Cretaceous.

Appraisal of the fossil record ofHomarus(nephropid lobster), with description of a new species from the upper Oligocene of Hungary and remarks on the status ofHoploparia

2017 ◽  
Vol 92 (2) ◽  
pp. 170-182 ◽  
Author(s):  
Dale Tshudy ◽  
Matúš Hyžný ◽  
Alfréd Dulai ◽  
John W.M. Jagt
Keyword(s):  
New Species ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Western Europe ◽  
Fossil Species ◽  
Upper Oligocene ◽  
Extant Species ◽  
The Status ◽  
A New Species

AbstractThe fossil record of the clawed lobster genus,Homarus, is appraised. The taxonomic history ofHomarusandHoplopariais summarized, and a list of species recognized for each is provided. A tabulation of all fossil species of the family Nephropidae permits assessment of nephropid species diversity through time. A new species ofHomarus,H.hungaricus, is recorded from the upper Oligocene (Chattian) Mány Formation at Mány, northern Hungary. The species is known by a single specimen consisting of a partial cephalothorax, a pleon minus telson, and partial chelipeds.Homarusis now known by two extant species (H.americanusandH.gammarus) and six fossil taxa, one of Early Cretaceous (Albian;H.benedeni) and five of Cenozoic age (H.hungaricusn. sp.,H.klebsi,H.lehmanni,H.morrisi, andH.percyi). The new fossilHomarusdiffers from modern congeners in aspects of carapace and pleon ornamentation and, especially, cutter claw shape. This is the fourth Oligocene occurrence of a nephropid species; all areHomarusand all are from Western Europe.Homarusmakes its appearance in the fossil record in the Early Cretaceous (Albian) and then is not known again until the Paleogene, despite the fact that nephropid lobsters in general are well known from the Late Cretaceous. Nephropid lobsters are better known from the Cretaceous than from the Cenozoic. Both raw species numbers and numbers corrected (normalized) for epicontinental sea coverage show that shelf-dwelling nephropid lobsters were most diverse during the Late Cretaceous.

scholarly journals A remarkable short-snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131186 ◽  
Author(s):  
Scott D. Sampson ◽  
Eric K. Lund ◽  
Mark A. Loewen ◽  
Andrew A. Farke ◽  
Katherine E. Clayton
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Strong Support ◽  
Northern Region ◽  
New Taxon ◽  
Western North America ◽  
Postcranial Skeleton ◽  
Western Interior Seaway

The fossil record of centrosaurine ceratopsids is largely restricted to the northern region of western North America (Alberta, Montana and Alaska). Exceptions consist of single taxa from Utah ( Diabloceratops ) and China ( Sinoceratops ), plus otherwise fragmentary remains from the southern Western Interior of North America. Here, we describe a remarkable new taxon, Nasutoceratops titusi n. gen. et sp., from the late Campanian Kaiparowits Formation of Utah, represented by multiple specimens, including a nearly complete skull and partial postcranial skeleton. Autapomorphies include an enlarged narial region, pneumatic nasal ornamentation, abbreviated snout and elongate, rostrolaterally directed supraorbital horncores. The subrectangular parietosquamosal frill is relatively unadorned and broadest in the mid-region. A phylogenetic analysis indicates that Nasutoceratops is the sister taxon to Avaceratops , and that a previously unknown subclade of centrosaurines branched off early in the group's history and persisted for several million years during the late Campanian. As the first well-represented southern centrosaurine comparable in age to the bulk of northern forms, Nasutoceratops provides strong support for the provincialism hypothesis, which posits that Laramidia—the western landmass formed by inundation of the central region of North America by the Western Interior Seaway—hosted at least two coeval dinosaur communities for over a million years of late Campanian time.

scholarly journals Prootic anatomy of a juvenile tyrannosauroid from New Jersey and its implications for the morphology and evolution of the tyrannosauroid braincase

2018 ◽  
Author(s):  
Chase D Brownstein
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Northern Hemisphere ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Fossil Record ◽  
Atlantic Coastal Plain ◽  
Western Interior Seaway ◽  
Large Predator ◽  
Atlantic Coastal

Among the most recognizable theropods are the tyrannosauroids, a group of small to large carnivorous coelurosaurian dinosaurs that inhabited the majority of the northern hemisphere during the Cretaceous and came to dominate large predator niches in North American and Asian ecosystems by the end of the Mesozoic era. The clade is among the best-represented of dinosaur groups in the notoriously sparse fossil record of Appalachia, the Late Cretaceous landmass that occupied the eastern portion of North America after its formation from the transgression of the Western Interior Seaway. Here, the prootic of a juvenile tyrannosauroid collected from the middle-late Campanian Marshalltown Formation of the Atlantic Coastal Plain is described, remarkable for being the first concrete evidence of juvenile theropods in that plain during the time of the existence of Appalachia and the only portion of theropod braincase known from the landmass. Phylogenetic analysis recovers the specimen as an “intermediate” tyrannosauroid of similar grade to Dryptosaurus and Appalachiosaurus. Comparisons with the corresponding portions of other tyrannosauroid braincases suggest that the Ellisdale prootic is more similar to Turonian forms in morphology than to the derived tyrannosaurids of the Late Cretaceous, thus supporting the hypothesis that Appalachian tyrannosauroids and other vertebrates were relict forms surviving in isolation from their derived counterparts in Eurasia.

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