Mammals from the Upper Cretaceous Oldman Formation, Alberta. II. Pediomys Marsh (Marsupialia)

1979 ◽  
Vol 16 (1) ◽  
pp. 103-113 ◽  
Author(s):  
Richard C. Fox
Keyword(s):  
South America ◽  
Upper Cretaceous ◽  
Therian Mammal ◽  
Direct Ancestor

Pediomys Marsh, a primitive marsupicarnivore, is the most common therian mammal known from the Upper Cretaceous Oldman Formation, Alberta, where it is represented by at least four species. The first, P. clemensi Sahni, appears closely related to the Lancian P. cooki Clemens; other species, poorly represented by fossils, resemble the Lancian P. elegans Marsh and P. hatcheri respectively; a final species, which is new, is interpreted as the direct ancestor of the Lancian P. krejcii Clemens. Pediomys shows trends toward enhancement of a crushing rather than a shearing function of the postcanine dentition and, consequently, seems not ancestral to the Cenozoic 'dog-like' marsupials of Australia and South America, contrary to recent suggestions elsewhere.

The Cretaceous and Paleocene pleurotomariid (Gastropoda: Vetigastropoda) fauna of Seymour Island, Antarctica

2009 ◽  
Vol 83 (5) ◽  
pp. 750-766 ◽  
Author(s):  
M. G. Harasewych ◽  
Anton Oleinik ◽  
William Zinsmeister
Keyword(s):  
Species Richness ◽  
New Zealand ◽  
South America ◽  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Southern India ◽  
New Combination ◽  
The Family ◽  
The Status ◽  
Seymour Island

Leptomaria antipodensis and Leptomaria hickmanae are described from the Upper Cretaceous [Maastrichtian] Lopez de Bertodano Formation, Seymour Island, and represent the first Mesozoic records of the family Pleurotomariidae from Antarctica. Leptomaria stillwelli, L. seymourensis, Conotomaria sobralensis and C. bayeri, from the Paleocene [Danian], Sobral Formation, Seymour Island, are described as new. Leptomaria larseniana (Wilckens, 1911) new combination, also from the Sobral Formation, is redescribed based on better-preserved material. The limited diversity of the pleurotomariid fauna of Seymour Island is more similar to that of the Late Cretaceous faunas of Australia and New Zealand in terms of the number of genera and species, than to the older, more diverse faunas of South America, southern India, or northwestern Madagascar, supporting the status of the Weddelian Province as a distinct biogeographic unit. The increase in the species richness of this fauna during the Danian may be due to the final fragmentation of Gondwana during this period.

A new, unusual therian mammal from the Upper Cretaceous of Saskatchewan, Canada

2007 ◽  
Vol 28 (5) ◽  
pp. 821-829 ◽  
Author(s):  
Richard C. Fox ◽  
Craig S. Scott ◽  
Harold N. Bryant
Keyword(s):  
Upper Cretaceous ◽  
Therian Mammal

scholarly journals New predatory cockroaches (Insecta: Blattaria: Manipulatoridae fam.n.) from the Upper Cretaceous Myanmar amber

2015 ◽  
Vol 66 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Peter Vršanský ◽  
Günter Bechly
Keyword(s):  
Upper Cretaceous ◽  
Sister Group ◽  
Side Branch ◽  
Crown Group ◽  
New Family ◽  
Stem Group ◽  
Direct Ancestor

Abstract We describe a new extinct lineage Manipulatoridae (new family) of cockroaches from the Upper Cretaceous (Cenomanian) amber of Myanmar. Manipulator modificaputis gen. et sp. n. is a morphologically unique extinct cockroach that represents the first (of a total of 29 known worldwide) cockroach family reported exclusively from the Myanmar amber. This family represents an early side branch of the stem group of Mantodea (most probably a sister group of Eadiidae within Blattaria/Corydioidea) because it has some synapomorphies with the Mantodea (including the stem group and Eadiidae). This family also retains symplesiomorphies that exclude a position in the crown group, and furthermore has unique autapomorphies that exclude a position as a direct ancestor of Mantodea. The unique adaptations such as strongly elongated extremities and freely movable head on a long neck suggest that these animals were pursuit predators. Five additional specimens (including two immatures) reported from the Myanmar amber suggest that this group was relatively rare but belonged to the indigenous and autochthonous inhabitants of the ancient amber forest of the Myanmar region.

scholarly journals Exquisite air sac histological traces in a hyperpneumatized nanoid sauropod dinosaur from South America

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tito Aureliano ◽  
Aline M. Ghilardi ◽  
Bruno A. Navarro ◽  
Marcelo A. Fernandes ◽  
Fresia Ricardi-Branco ◽  
...  
Keyword(s):  
Computed Tomography ◽  
South America ◽  
Ct Scan ◽  
Upper Cretaceous ◽  
Postcranial Skeleton ◽  
Air Sacs ◽  
Neural Canal ◽  
Scan Data ◽  
Pneumatic Structures ◽  
First Time

AbstractThis study reports the occurrence of pneumosteum (osteohistological structure related to an avian-like air sac system) in a nanoid (5.7-m-long) saltasaurid titanosaur from Upper Cretaceous Brazil. We corroborate the hypothesis of the presence of an air sac system in titanosaurians based upon vertebral features identified through external observation and computed tomography. This is the fifth non-avian dinosaur taxon in which histological traces of air sacs have been found. We provided a detailed description of pneumatic structures from external osteology and CT scan data as a parameter for comparison with other taxa. The camellate pattern found in the vertebral centrum (ce) of this taxon and other titanosaurs shows distinct architectures. This might indicate whether cervical or lung diverticula pneumatized different elements. A cotylar internal plate of bone tissue sustains radial camellae (rad) in a condition similar to Alamosaurus and Saltasaurus. Moreover, circumferential chambers (cc) near the cotyle might be an example of convergence between diplodocoids and titanosaurs. Finally, we also register for the first time pneumatic foramina (fo) and fossae connecting camellate structures inside the neural canal in Titanosauria and the second published case in non-avian dinosaurs. The extreme pneumaticity observed in this nanoid titanosaur contrasts with previous assumptions that this feature correlates with the evolution of gigantic sizes in sauropodomorphs. This study reinforces that even small-bodied sauropod clades could present a hyperpneumatized postcranial skeleton, a character inherited from their large-bodied ancestors.

Influence of taphonomy on histological evidence for vertebral pneumaticity in an Upper Cretaceous titanosaur from South America

2020 ◽  
Vol 108 ◽  
pp. 104337 ◽  
Author(s):  
Tito Aureliano ◽  
Aline M. Ghilardi ◽  
Julian C.G. Silva-Junior ◽  
Agustín G. Martinelli ◽  
Luiz Carlos Borges Ribeiro ◽  
...  
Keyword(s):  
South America ◽  
Upper Cretaceous ◽  
Histological Evidence

Upper Cretaceous Fossil Molluscs in South America and West Africa

Nature ◽  
1965 ◽  
Vol 207 (5004) ◽  
pp. 1384-1384 ◽  
Author(s):  
R. A. REYMENT
Keyword(s):  
South America ◽  
West Africa ◽  
Upper Cretaceous
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