scholarly journals A new atoposaurid crocodylomorph from the Morrison Formation (Upper Jurassic) of Wyoming, USA

2018 ◽  
Vol 5 ◽  
pp. 287-295 ◽  
Author(s):  
John R. Foster
Keyword(s):  
New Species ◽  
North America ◽  
Upper Jurassic ◽  
Morrison Formation ◽  
Unique Combination ◽  
Lower Jaw ◽  
Left Mandible ◽  
First Occurrence

A left mandible of a small crocodyliform found in the Upper Jurassic Morrsion Formation of northeastern Wyoming represents the first occurrence of the atoposaurid Theriosuchus in North America. The specimen demonstrates lower jaw morphology, including heterodonty (as indicated by alveolus shape), similar to Theriosuchus and Knoetschkesuchus, but autapomorphies and a unique combination of characters among these taxa indicate that it is a distinct, new species of Theriosuchus.

scholarly journals A new atoposaurid crocodylomorph from the Morrison Formation (Upper Jurassic) of Wyoming, USA

2018 ◽  
Vol 5 ◽  
pp. 287-295 ◽  
Author(s):  
John Foster
Keyword(s):  
New Species ◽  
North America ◽  
Upper Jurassic ◽  
Morrison Formation ◽  
Unique Combination ◽  
Lower Jaw ◽  
Left Mandible ◽  
First Occurrence

A left mandible of a small crocodyliform found in the Upper Jurassic Morrsion Formation of northeastern Wyoming represents the first occurrence of the atoposaurid Theriosuchus in North America. The specimen demonstrates lower jaw morphology, including heterodonty (as indicated by alveolus shape), similar to Theriosuchus and Knoetschkesuchus, but autapomorphies and a unique combination of characters among these taxa indicate that it is a distinct, new species of Theriosuchus.

scholarly journals Cranial anatomy of Allosaurus jimmadseni, a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North America

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e7803 ◽  
Author(s):  
Daniel J. Chure ◽  
Mark A. Loewen
Keyword(s):  
New Species ◽  
North America ◽  
Phylogenetic Analyses ◽  
Upper Jurassic ◽  
Morrison Formation ◽  
Ventral Margin ◽  
Western North America ◽  
Theropod Dinosaur ◽  
Theropod Dinosaurs ◽  
A New Species

Allosaurus is one of the best known theropod dinosaurs from the Jurassic and a crucial taxon in phylogenetic analyses. On the basis of an in-depth, firsthand study of the bulk of Allosaurus specimens housed in North American institutions, we describe here a new theropod dinosaur from the Upper Jurassic Morrison Formation of Western North America, Allosaurus jimmadseni sp. nov., based upon a remarkably complete articulated skeleton and skull and a second specimen with an articulated skull and associated skeleton. The present study also assigns several other specimens to this new species, Allosaurus jimmadseni, which is characterized by a number of autapomorphies present on the dermal skull roof and additional characters present in the postcrania. In particular, whereas the ventral margin of the jugal of Allosaurus fragilis has pronounced sigmoidal convexity, the ventral margin is virtually straight in Allosaurus jimmadseni. The paired nasals of Allosaurus jimmadseni possess bilateral, blade-like crests along the lateral margin, forming a pronounced nasolacrimal crest that is absent in Allosaurus fragilis.

First fossil orthoptera from the Jurassic of North America

2011 ◽  
Vol 85 (1) ◽  
pp. 102-105 ◽  
Author(s):  
Dena M. Smith ◽  
Mark A. Gorman ◽  
Jason D. Pardo ◽  
Bryan J. Small
Keyword(s):  
New Species ◽  
North America ◽  
Upper Jurassic ◽  
The Other ◽  
Morrison Formation ◽  
The Family ◽  
A New Species

A new species of Orthoptera,Parapleurites morrisonensis, is described from the upper Jurassic Morrison Formation of Colorado, USA. This is the first insect described from the Morrison Formation and the first orthopteran described from the Jurassic of North America. No other members of the family Locustopsidae have been described in North America previously, and the other species ofParapleuritesare only known from Siberia. The lack of Jurassic Orthoptera in North America is likely due to a combination of taphonomic variables and collector bias. The discovery ofParapleurites morrisonensisand the potential for finding other Jurassic Orthoptera are important to understanding the evolution of this diverse and widely distributed group.

scholarly journals An unusually diverse northern biota from the Morrison Formation (Upper Jurassic), Black Hills, Wyoming

2020 ◽  
Vol 7 ◽  
pp. 29-67
Author(s):  
John Foster ◽  
Darrin Pagnac ◽  
ReBecca Hunt-Foster
Keyword(s):  
North America ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
River Channel ◽  
Black Hills ◽  
Morrison Formation ◽  
Vertebrate Fauna ◽  
Type Area ◽  
First Occurrence

The Little Houston Quarry in the Black Hills of Wyoming contains the most diverse vertebrate fauna in the Morrison Formation (Upper Jurassic) north of Como Bluff and the second-most diverse in the entire formation, after Reed’s Quarry 9. The deposit was an occasionally reactivated abandoned river channel, in interbedded green mudstone and laminated green-gray siltstone above a channel sandstone. The dinosaur material is densely distributed and is disarticulated to articulated, with several associated skeletons. The biota contains charophytes, horsetails, a possible seed fern, possible conifers, gastropods, two types of unionoid bivalves, diplostracans (“conchostracans”), a malacostracan, ray-finned fish, lungfish, a frog, salamanders, two types of turtles, rhynchocephalians, a lizard, choristoderes, two types of crocodyliforms, a pterosaur, Allosaurus and several types of small theropods including Tanycolagreus? and probable dromaeosaurids, numerous Camarasaurus and a diplodocine sauropod, a stegosaur, the neornithischian Nanosaurus, and the mammals Docodon, Amblotherium, and a multituberculate. Among these taxa, one of the unionoid bivalves, an atoposaurid crocodyliform, and the species of Amblotherium, which appear to be new and unique to the locality so far. The Docodon material may represent the first occurrence of D. apoxys outside of its type area in Colorado. Additionally, small, unusual theropod tooth types reported here may represent the first Late Jurassic occurrence of cf. Richardoestesia in North America and a possible abelisauroid, respectively.

Mytiloides hattini n. sp.: a guide fossil for the base of the Turonian in the Western Interior of North America

1991 ◽  
Vol 65 (2) ◽  
pp. 234-241 ◽  
Author(s):  
William P. Elder
Keyword(s):  
New Species ◽  
North America ◽  
Western Europe ◽  
Upper Cretaceous ◽  
First Occurrence ◽  
A New Species ◽  
Stratigraphic Interval

Mytiloides hattini, a new species of inoceramid bivalve from the basal Turonian (Upper Cretaceous), is described and its stratigraphic importance discussed. This inoceramid is particularly significant because its first occurrence can be used as a marker for the base of the Turonian in strata that typically contain no ammonites and few other taxa. The lowest occurrence of Mytiloides hattini is characterized by abundant specimens over wide regions of the Western Interior of North America; this species also apparently occurs in the lowest Turonian strata of western Europe. The typical absence of ammonites in this stratigraphic interval potentially makes the first occurrence of Mytiloides hattini an important fossil for regional and intercontinental correlation of the Cenomanian–Turonian boundary.

A New Species of Marine Triclad Turbellarian of the Genus Sabussowia from Prince Edward Island

1973 ◽  
Vol 30 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Ian R. Ball
Keyword(s):  
New Species ◽  
North America ◽  
Prince Edward Island ◽  
The Status ◽  
First Occurrence ◽  
Nomina Dubia ◽  
A New Species

A new species of marine triclad turbellarian, Sabussowia wilhelmii sp. nov., is described from the Pisquid River, Prince Edward Island, Canada. This represents the first occurrence of the genus and of the subfamily Cercyrinae of the Procerodidae in North America. The genus is discussed and a key to the known species is provided. A detailed discussion of the status of Vortex warreni of Girard and Procerodes warreni of Wilhelmi is given. The identity of the former cannot be ascertained. The latter could be a Sabussowia species, but, in the absence of fully mature material, this question cannot be resolved. Both names are regarded as nomina dubia, and the suppression of the genus Fovia of Girard is recommended.

Sign in / Sign up

Export Citation Format

Share Document