scholarly journals A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7247 ◽  
Author(s):  
Scott Hartman ◽  
Mickey Mortimer ◽  
William R. Wahl ◽  
Dean R. Lomax ◽  
Jessica Lippincott ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
New Taxon ◽  
Morrison Formation ◽  
Postcranial Skeleton ◽  
Avian Flight ◽  
Multiple Alternative ◽  
Limb Proportions

The last two decades have seen a remarkable increase in the known diversity of basal avialans and their paravian relatives. The lack of resolution in the relationships of these groups combined with attributing the behavior of specialized taxa to the base of Paraves has clouded interpretations of the origin of avialan flight. Here, we describeHesperornithoides miesslerigen. et sp. nov., a new paravian theropod from the Morrison Formation (Late Jurassic) of Wyoming, USA, represented by a single adult or subadult specimen comprising a partial, well-preserved skull and postcranial skeleton. Limb proportions firmly establishHesperornithoidesas occupying a terrestrial, non-volant lifestyle. Our phylogenetic analysis emphasizes extensive taxonomic sampling and robust character construction, recovering the new taxon most parsimoniously as a troodontid close toDaliansaurus,Xixiasaurus, andSinusonasus. Multiple alternative paravian topologies have similar degrees of support, but proposals of basal paravian archaeopterygids, avialan microraptorians, andRahonavisbeing closer to Pygostylia than archaeopterygids or unenlagiines are strongly rejected. All parsimonious results support the hypothesis that each early paravian clade was plesiomorphically flightless, raising the possibility that avian flight originated as late as the Late Jurassic or Early Cretaceous.

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.

scholarly journals Origin and evolution of turiasaur dinosaurs set by means of a new ‘rosetta’ specimen from Spain

2020 ◽  
Vol 191 (1) ◽  
pp. 201-227
Author(s):  
Rafael Royo-Torres ◽  
Alberto Cobos ◽  
Pedro Mocho ◽  
Luis Alcalá
Keyword(s):  
North America ◽  
19Th Century ◽  
Early Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
Postcranial Skeleton ◽  
Early 19Th Century ◽  
Origin And Evolution ◽  
Character Variation ◽  
The Usa

Abstract Turiasauria is a non-neosauropod eusauropod clade of dinosaurs known since 2006, when the description of Turiasaurus was published. This group, including Losillasaurus, was originally thought to have been restricted to the Late Jurassic of Spain. However, over the last decade, our knowledge of this group has improved with the discovery of new taxa such as Zby from the Portuguese Late Jurassic, Tendaguria from the Tanzanian Late Jurassic and Mierasaurus and Moabosaurus from the Early Cretaceous of the USA. Here, we describe a new specimen of Losillasaurus from Spain, which allows us to better understand the character variation in the cranial and postcranial skeleton. The review of some sauropod fauna of Madagascar, and inclusion of some specimens of Turiasauria, suggest that this clade might have arisen in the Middle Jurassic. According to our phylogenetic results, a specimen found in the early 19th century in Madagascar is shown to be the oldest and only member of Turiasauria represented in the Middle Jurassic thus far. This is named Narindasaurus thevenini gen. & sp. nov.. Turiasauria is thus known from the Middle Jurassic in Pangaea, diversified in the Late Jurassic in Gondwana and Laurasia, and dispersed during the Early Cretaceous to North America.

scholarly journals A possible brachiosaurid (Dinosauria, Sauropoda) from the mid-Cretaceous of northeastern China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11957
Author(s):  
Chun-Chi Liao ◽  
Andrew Moore ◽  
Changzhu Jin ◽  
Tzu-Ruei Yang ◽  
Masateru Shibata ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
North America ◽  
Early Cretaceous ◽  
Northeast China ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Convincing Evidence ◽  
Northeastern China

Brachiosauridae is a lineage of titanosauriform sauropods that includes some of the most iconic non-avian dinosaurs. Undisputed brachiosaurid fossils are known from the Late Jurassic through the Early Cretaceous of North America, Africa, and Europe, but proposed occurrences outside this range have proven controversial. Despite occasional suggestions that brachiosaurids dispersed into Asia, to date no fossils have provided convincing evidence for a pan-Laurasian distribution for the clade, and the failure to discover brachiosaurid fossils in the well-sampled sauropod-bearing horizons of the Early Cretaceous of Asia has been taken to evidence their genuine absence from the continent. Here we report on an isolated sauropod maxilla from the middle Cretaceous (Albian–Cenomanian) Longjing Formation of the Yanji basin of northeast China. Although the specimen preserves limited morphological information, it exhibits axially twisted dentition, a shared derived trait otherwise known only in brachiosaurids. Referral of the specimen to the Brachiosauridae receives support from phylogenetic analysis under both equal and implied weights parsimony, providing the most convincing evidence to date that brachiosaurids dispersed into Asia at some point in their evolutionary history. Inclusion in our phylogenetic analyses of an isolated sauropod dentary from the same site, for which an association with the maxilla is possible but uncertain, does not substantively alter these results. We consider several paleobiogeographic scenarios that could account for the occurrence of a middle Cretaceous Asian brachiosaurid, including dispersal from either North America or Europe during the Early Cretaceous. The identification of a brachiosaurid in the Longshan fauna, and the paleobiogeographic histories that could account for its presence there, are hypotheses that can be tested with continued study and excavation of fossils from the Longjing Formation.

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.

New multituberculate mammal from the Early Cretaceous of eastern North America

2013 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Richard L. Cifelli ◽  
Cynthia L. Gordon ◽  
Thomas R. Lipka
Keyword(s):  
North America ◽  
Iberian Peninsula ◽  
Early Cretaceous ◽  
North American ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Relative Length ◽  
Central Position ◽  
Eastern North America ◽  
The North

Multituberculates, though among the most commonly encountered mammalian fossils of the Mesozoic, are poorly known from the North American Early Cretaceous, with only one taxon named to date. Herein we describe Argillomys marylandensis, gen. et sp. nov., from the Early Cretaceous of Maryland, based on an isolated M2. Argillomys represents the second mammal known from the Arundel Clay facies of the Patuxent Formation (Lower Cretaceous: Aptian). Though distinctive in its combination of characters (e.g., enamel ornamentation consisting of ribs and grooves only, cusp formula 2:4, presence of distinct cusp on anterobuccal ridge, enlargement of second cusp on buccal row, central position of ultimate cusp in lingual row, great relative length), the broader affinities of Argillomys cannot be established because of non-representation of the antemolar dentition. Based on lack of apomorphies commonly seen among Cimolodonta (e.g., three or more cusps present in buccal row, fusion of cusps in lingual row, cusps strongly pyramidal and separated by narrow grooves), we provisionally regard Argillomys as a multituberculate of “plagiaulacidan” grade. Intriguingly, it is comparable in certain respects to some unnamed Paulchoffatiidae, a family otherwise known from the Late Jurassic – Early Cretaceous of the Iberian Peninsula.

The systematic position of the Late Jurassic alleged dinosaur Macelognathus (Crocodylomorpha: Sphenosuchia)

2005 ◽  
Vol 42 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Ursula B Göhlich ◽  
Luis M Chiappe ◽  
James M Clark ◽  
Hans-Dieter Sues
Keyword(s):  
Late Jurassic ◽  
Upper Jurassic ◽  
Systematic Position ◽  
Lower Jurassic ◽  
Late Triassic ◽  
Morrison Formation ◽  
Postcranial Skeleton ◽  
Western Colorado ◽  
New Material ◽  
Limb Posture

Macelognathus vagans was described by O.C. Marsh in 1884, based on a mandibular symphysis from the Upper Jurassic Morrison Formation of Wyoming. Often considered a dinosaur but later tentatively referred to the Crocodylia, its phylogenetic identity has until now been enigmatic. New material of this species from the Morrison Formation of western Colorado demonstrates its affinities with basal crocodylomorphs commonly grouped together as the Sphenosuchia, which are characterized by a gracile postcranial skeleton with erect limb posture. Macelognathus shares features with Kayentasuchus from the Lower Jurassic Kayenta Formation of Arizona and Hallopus, which may be from the Morrison Formation of eastern Colorado. The new material constitutes the youngest definitive occurrence of a sphenosuchian, previously known from the Late Triassic to the Middle or Late? Jurassic.

scholarly journals <i>Praecypridea</i>: a new non-marine ostracod genus from the Jurassic and Early Cretaceous of Europe, North and South America, and Africa

2010 ◽  
Vol 29 (2) ◽  
pp. 163-176 ◽  
Author(s):  
Benjamin Sames ◽  
Robin Whatley ◽  
Michael E. Schudack
Keyword(s):  
North America ◽  
South America ◽  
Early Cretaceous ◽  
Type Species ◽  
Late Jurassic ◽  
New Genus ◽  
Marine Habitats ◽  
Extinct Genus ◽  
North And South America ◽  
North And South

Abstract. The genus Praecypridea gen. nov. (Cypridoidea, Family Cyprideidae Martin, 1940) is described and thus far comprises four species: the type species Praecypridea acuticyatha (Schudack, 1998) comb. nov., Praecypridea postelongata (Oertli, 1957) comb. nov., Praecypridea suprajurassica (Mojon, Haddoumi &amp; Charriére, 2009) comb. nov. and Praecypridea acuta (Moos, 1959 in Wicher, 1959) comb. nov. Representatives of the new genus have been described from the Middle to Late Jurassic of Europe, North America and Africa and the Early Cretaceous of South America, with other presumed representatives also occurring in the Early Cretaceous. Species of Praecypridea are considered to represent members of the ancestral lineage of the extinct genus Cypridea Bosquet, representatives of which flourished in non-marine habitats of latest Jurassic to Early Cretaceous age and account for the first period of abundance of the non-marine Cypridoidea.

scholarly journals A Late Jurassic salamander (Amphibia: Caudata) from the Morrison Formation of North America

2005 ◽  
Vol 143 (4) ◽  
pp. 599-616 ◽  
Author(s):  
S. E. EVANS ◽  
C. LALLY ◽  
D. C. CHURE ◽  
A. ELDER ◽  
J. A. MAISANO
Keyword(s):  
North America ◽  
Late Jurassic ◽  
Morrison Formation

scholarly journals Redescription of Arundel formation Ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an “Ostrich Dinosaur”: Biogeographic implications

2016 ◽  
Author(s):  
Chase Doran Brownstein
Keyword(s):  
United States ◽  
North America ◽  
Early Cretaceous ◽  
Fossil Record ◽  
East Coast ◽  
The United States ◽  
Eastern North America ◽  
New Taxon ◽  
Western North America ◽  
The Past

The fossil record of dinosaurs from the Early Cretaceous of eastern North America is scant, and only a few sediments to the east of the continent are fossiliferous. Among them is the Arundel Formation of the east coast of the United States, which has produced among the best dinosaur faunas known from the Early Cretaceous of eastern North America. The diverse dinosaur fauna of this formation has been thoroughly discussed previously, but few of the dinosaur species originally described from the Arundel are still regarded as valid genera. Much of the Arundel material is in need of review and redescription. Among the fossils of dinosaurs from this formation are those referred to ornithomimosaurs. Here, I redescribe ornithomimosaur remains from the Arundel Formation which may warrant the naming of a new taxon of dinosaur. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. The description of the Arundel material herein along with recent discoveries of basal ornithomimosaurs in the past 15 years has allowed for comparisons with the coelurosaur Nedcolbertia justinhofmanni, suggesting the latter animal was a basal ornithomimosaurian dinosaur rather than a “generalized” coelurosaur. Comparisons between the Arundel ornithomimosaur and similar southeast Asian ornithomimosaurian material as well as ornithomimosaur remains from western North America suggest that a lineage of ornithomimosaurs with a metatarsal condition intermediate between that of basal and derived ornithomimosaurs was present through southeast Asia into North America, in turn suggesting that such animals coexisted with genera having a more primitive metatarsal morphology as seen in N. justinhofmanni.

Sign in / Sign up

Export Citation Format

Share Document