scholarly journals Redescription and affinities ofHulsanpes perlei(Dinosauria, Theropoda) from the Upper Cretaceous of Mongolia

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4868 ◽  
Author(s):  
Andrea Cau ◽  
Daniel Madzia
Keyword(s):  
Inner Ear ◽  
Upper Cretaceous ◽  
Unique Combination ◽  
Theropod Dinosaur ◽  
The Third ◽  
Valid Taxon ◽  
Multiple Species ◽  
Upper Campanian

Hulsanpes perleiis an enigmatic theropod dinosaur from the Baruungoyot Formation (?mid- to upper Campanian, Upper Cretaceous) of Mongolia. It was discovered in 1970, during the third Polish-Mongolian paleontological expedition to the Nemegt Basin. The taxon is known based on a partial braincase and an incomplete right hindlimb. However, the braincase fragment has never been described nor illustrated. We redescribe all elements that form the holotype ofHulsanpesand discuss the affinities of this taxon. The braincase fragment is interpreted as belonging to the inner ear region, and includes the floccular recess and part of the labyrinth.Hulsanpes perleiis confirmed as a valid taxon, diagnosed by a unique combination of metatarsal characters, including two autapomorphies. Historically, it represents the oldest record of the recently-established clade Halszkaraptorinae. Our findings identify subcursorial adaptations forHulsanpes, shared withMahakala,and differentiating them fromHalszkaraptor. As such, appendicular disparity in the potentially sympatric halszkaraptorines suggest a reduced ecological overlap among these taxa, which may explain the co-occurrence of multiple species of this clade during the latest Cretaceous in what is now the Nemegt Basin.

scholarly journals The phylogenetic affinities and morphological peculiarities of the bird-like dinosaur Borogovia gracilicrus from the Upper Cretaceous of Mongolia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12640
Author(s):  
Andrea Cau ◽  
Daniel Madzia
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Distal Part ◽  
The Other ◽  
Theropod Dinosaur ◽  
Distinctive Morphology ◽  
Valid Taxon ◽  
Phylogenetic Affinities ◽  
Second Toe

Borogovia gracilicrus is a small-bodied theropod dinosaur from the Maastrichtian (Upper Cretaceous) Nemegt Formation of southern Mongolia. The taxon is based on a single fragmentary specimen preserving only the distal part of the hindlimbs. The morphology of Borogovia shows a peculiar combination of features, some of which are traditionally considered troodontid synapomorphies and others which are unusual for Troodontidae but are shared with other maniraptoran clades. In particular, the second toe of B. gracilicrus differs from other troodontids in lacking some of the features which contribute to the specialized ‘sickle-clawed’ second toe, here termed the ‘falciphoran condition’, shared with dromaeosaurids and some other paravians, such as the strongly compressed and falciform ungual. Phylogeny reconstructions intended to explore the affinities of Borogovia consistently support its referral within a subclade of troodontids including all Late Cretaceous taxa. The placement of Borogovia is not significantly affected by its unusual combinations of hindlimb features or by the homoplasy of the elements forming the falciphoran condition. Borogovia is supported as a valid taxon and is distinct from the other Nemegt troodontids, Tochisaurus and Zanabazar. The lack of a falciform ungual, and the distinctive morphology of the second toe in B. gracilicrus are interpreted as a derived specialization among Troodontidae and not as retention of the plesiomorphic condition of non-paravian theropods.

The first appearance of Troodon in the Upper Cretaceous site of Danek Bonebed, and a reevaluation of troodontid quantitative tooth morphotypes

2014 ◽  
Vol 51 (11) ◽  
pp. 1039-1044 ◽  
Author(s):  
Angelica Torices ◽  
Gregory F. Funston ◽  
Shannon T. Kraichy ◽  
Philip J. Currie
Keyword(s):  
Upper Cretaceous ◽  
Systematic Position ◽  
Sister Taxon ◽  
Theropod Dinosaur ◽  
Single Tooth ◽  
Horseshoe Canyon Formation ◽  
Upper Campanian

The systematic position of the small theropod dinosaur Troodon has had a confusing history and has been identified at different times as a lizard, a pachycephalosaurid, and a coelurosaurid. Troodon is now most commonly considered as a sister taxon to Dromeaosauridae, within Maniraptora. This study records the first evidence of Troodon in the Danek bonebed, an organic-rich member of the upper Campanian Horseshoe Canyon Formation. A single tooth (UALVP 55489) was recovered during the 2012 dig season, and it is exceptionally well-preserved. Its discovery prompted a reevaluation of variation within troodontid teeth in Alberta; it is compared here with 110 troodontid teeth from the Dinosaur Park, Horseshoe Canyon, and Wapiti formations. The results show that no distinctive morphotypes can be separated, in contrast to the results of other studies. This suggests that either troodontid teeth are not sufficiently different for identifying different species or that only one troodontid taxon is present in the Campanian of Alberta.

Adding the Third Dimension to High Resolution MR-Imaging of the Inner Ear: An Answer waiting for a question

2013 ◽  
Vol 185 (S 01) ◽  
Author(s):  
NN Naguib ◽  
NE Nour-Eldin ◽  
T Gruber-Rouh ◽  
T Lehnert ◽  
R Hammerstingl ◽  
...  
Keyword(s):  
High Resolution ◽  
Mr Imaging ◽  
Inner Ear ◽  
The Third ◽  
Third Dimension

Quantitative diagenetic analyses of Edmontosaurus regalis (Dinosauria: Hadrosauridae) postcranial elements from the Danek Bonebed, Upper Cretaceous Horseshoe Canyon Formation, Edmonton, Alberta, Canada: implications for allometric studies of fossil organisms

2014 ◽  
Vol 51 (11) ◽  
pp. 1007-1016 ◽  
Author(s):  
Mackenzie Baert ◽  
Michael E. Burns ◽  
Philip J. Currie
Keyword(s):  
Cross Section ◽  
Upper Cretaceous ◽  
Strong Relationship ◽  
Major Axis ◽  
Minor Axis ◽  
Morphological Features ◽  
Fossil Assemblages ◽  
Fossil Vertebrate ◽  
Horseshoe Canyon Formation ◽  
Upper Campanian

For fossil assemblages, quantitative size and shape studies are often complicated by diagenetic distortion. Different vertebrate elements, although subjected to similar burial stresses, exhibit deformations based upon their original shapes; this hypothesis is tested here by quantitatively comparing deformed humeri and femora from the Danek Bonebed (a monodominant Edmontosaurus regalis bonebed from the upper Campanian Horseshoe Canyon Formation in Edmonton, Alberta, Canada) with samples of undeformed humeri and femora from modern and fossil assemblages. Analyses suggest that at the Danek Bonebed a strong relationship exists between element length and circumference despite being distorted by crushing deformation. Major and minor axes of the midshaft cross section, however, were not uniformly distorted. Although their anatomical position did not change, the major axis became longer relative to the minor axis in distorted specimens. A regression based on the undeformed humeri was not able to accurately predict circumference in the Danek humeri. Further study might quantify the deformation of other bones in the Danek Bonebed and could be extended to other assemblages and genera. Caution should be taken when conducting studies in which diagenetic crushing may have altered morphological features of fossil vertebrate remains.

Histologic growth dynamic study of Edmontosaurus regalis (Dinosauria: Hadrosauridae) from a bonebed assemblage of the Upper Cretaceous Horseshoe Canyon Formation, Edmonton, Alberta, Canada

2014 ◽  
Vol 51 (11) ◽  
pp. 1023-1033 ◽  
Author(s):  
Evan Vanderven ◽  
Michael E. Burns ◽  
Philip J. Currie
Keyword(s):  
Life History ◽  
Body Size ◽  
Upper Cretaceous ◽  
Growth Dynamics ◽  
Growth Dynamic ◽  
History Data ◽  
Life History Data ◽  
Fundamental Systems ◽  
Horseshoe Canyon Formation ◽  
Upper Campanian

The Danek Bonebed (Edmonton, Alberta, Canada) is a monodominant Edmontosaurus regalis assemblage of the upper Campanian (Upper Cretaceous) Horseshoe Canyon Formation. Bone histology of humeri and femora are used in this paper to test hypotheses about the growth dynamics and palaeobiology of Edmontosaurus. The high number of elements collected from the Danek Bonebed allow for an expansion of the multi-element histological record for hadrosaurs. Results indicate that Edmontosaurus had a growth trajectory similar to other large-bodied dinosaurs and reached the onset of somatic maturity at about 10–15 years of age; however, even the largest elements to preserve lines of arrested growth do not have external fundamental systems. This timing of the onset of somatic maturity agrees with the estimated body size of Edmontosaurus relative to other dinosaurs for which life-history data are available. Vascularity patterns support the hypothesis that edmontosaurs preserved at the Danek Bonebed were not subject to the same extreme seasonal environmental shifts as congenerics preserved at higher latitudes, further supporting overwintering behaviour in the latter.

Parataxonomic classification of ornithoid eggshell fragments from the Oldman Formation (Judith River Group; Upper Cretaceous), southern Alberta

1996 ◽  
Vol 33 (12) ◽  
pp. 1655-1667 ◽  
Author(s):  
Darla K. Zelenitsky ◽  
L. V. Hills ◽  
Philip J. Currie
Keyword(s):  
Late Cretaceous ◽  
Shell Thickness ◽  
Upper Cretaceous ◽  
Theropod Dinosaur ◽  
Surface Sculpture ◽  
External Zone ◽  
Theropod Dinosaurs ◽  
Southern Alberta ◽  
The Family

Examination of a large number of eggshell fragments collected from the Oldman Formation of southern Alberta reveals a greater ootaxonomic diversity than is known from complete eggs or clutches. Three new oogenera and oospecies of the ornithoid-ratite morphotype and one of the ornithoid-prismatic morphotype are established, based on the eggshell fragments. Porituberoolithus warnerensis oogen. et oosp. nov. and Continuoolithus canadensis oogen. et oosp. nov. have a microstructure similar to that of elongatoolithid eggs of theropod dinosaurs. Tristraguloolithus cracioides oogen. et oosp. nov. and Dispersituberoolithus exilis oogen. et oosp. nov. possess an external zone and thus have a microstructure like modern avian eggshell. Tristraguloolithus has a shell thickness, microstructure, and surface sculpture similar to those of recent bird eggshell of the family Cracidae (order Galliformes). Dispersituberoolithus exhibits the primitive or normal eggshell condition of some recent neognathous avian taxa. The ootaxa described indicate a diversity of both avian and theropod dinosaur egg layers within Devil's Coulee and Knight's Ranch, southern Alberta, during the Late Cretaceous.

scholarly journals Speleogenesis and depositional hystory of paleokarst phreatic caves/cavities; Podgrad, SW Slovenia

2021 ◽  
Author(s):  
Bojan Otoničar
Keyword(s):  
Host Rock ◽  
Upper Cretaceous ◽  
Coarse Grained ◽  
Mixing Zone ◽  
Carbonate Sediment ◽  
Lower Eocene ◽  
The Third ◽  
Cave Sediments ◽  
Upper Paleocene ◽  
Δ13c And Δ18o

The studied palaeokarst corresponds to an uplifted peripheral foreland bulge when Upper Cretaceous diagenetically immature eugenetic carbonates were subaerially exposed, karstified and subsequently overlain by upper Paleocene/lower Eocene palustrine limestone. Among the subsurface paleokarstic features, both vadose and phreatic forms occur.  The phreatic caves/cavities include features characteristic of the mixing zone speleogenesis at the interface between freshwater (brackish water) lenses and the underlying seawater. They were found in various positions with respect to the paleokarstic surface, the deepest being about 75 m below the surface. Three indistinct horizons of cavities/caves and intermediate vugs were recognized. Subsequently, all cavities were completely filled with detrital sediments and speleothems in the phreatic and vadose zones. In general, the phreatic cavities of the lower two horizons are geopetally filled with mudstone derived from incomplete dissolution of the host rock and overlain by coarse-grained, blocky calcite. Shallower below the paleokarst surface, a large phreatic cave of the third horizon is filled with flowstone overlain by reddish micritic carbonate sediment with intercalated calcite rafts. In the upper part of the cave, sediments derived from the paleokarst surface are gradually becoming more abundant. Vadose channels, which may also intersect the cave sediments, are mainly filled with "pedogenic" material derived from the paleokarst surface. Immediately prior to marine transgression over the paleokarst surface, some cavities were filled with marine-derived microturbidites. In general, the diversity of cave fills and the amount of surface material decrease with distance from the paleokarst surface. Below the paleokarst surface, the δ13C and δ18O values of a host rock and cavity deposits show good correlation with trends significant for meteoric diagenesis. It is shown that deposits associated with phreatic caves can be of great importance for the study of the speleogenetic, geomorphological and hydrogeological evolution of certain palaeokarst regions.

A new marine clupeoid fish from the Lower Cretaceous of the Sergipe-Alagoas Basin, northeastern Brazil

Zootaxa ◽  
2009 ◽  
Vol 2164 (1) ◽  
pp. 21-32 ◽  
Author(s):  
FRANCISCO J. DE FIGUEIREDO
Keyword(s):  
Fossil Record ◽  
Upper Cretaceous ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Axial Skeleton ◽  
Northeastern Brazil ◽  
Unique Combination ◽  
Caudal Vertebrae ◽  
Clupeoid Fish ◽  
Marine Deposit

Clupeomorph fishes are largely diversified and widespread in Cretaceous strata of northeastern Brazil. They are represented by basal clupeiforms, †ellimmichthyiforms, and advanced clupeoids. In this paper, a new clupeoid fish, †Nolfia riachuelensis sp. nov., is described based on a specimen found in marine shale yielded in the Taquari Member (Albian) of Riachuelo Formation, Sergipe-Alagoas Basin. Although partially preserved (most of skull is lacking), the fish shows many informative characters, particularly in the axial skeleton. The fish is morphologically very similar to †Nolfia kwangoensis, a clupeoid fish originally described from marine deposit from the Upper Cretaceous (Cenomanian) of Kipala, Democratic Republic of Congo, with which it shares: 18 caudal vertebrae; long and cylindrical pleural ribs; posteriormost pleural ribs supported by long parapophyses and gradually decreasing in size posteriorly; very reduced ural centra; presence of long and distally congruent neural spines of third, second, and first preural centra; three uroneural bones (the first probably forming the pleurostyle). Otherwise, †Nolfia riachuelensis sp. nov. differs from other clupeomorphs by a unique combination of features. The number of supraneural bones, aligned rod-like postcleithra, less than 30 rays in the anal fin, and derived absence of dorsal scutes indicate its placement within Clupeidae. As far as is known, †Nolfia riachuelensis sp. nov. is the most ancient clupeoid fish known from the fossil record.

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