Several new fossil specimens from the Cambay Shale Formation at Tadkeshwar Lignite Mine in Gujara... more Several new fossil specimens from the Cambay Shale Formation at Tadkeshwar Lignite Mine in Gujarat document the presence of two previously unknown early Eocene primate species from India. A new species of Asiadapis is named based on a jaw fragment preserving premolars similar in morphology to those of A. cambayensis but substantially larger. Also described is an exceptionally preserved edentulous dentary (designated cf. Asiadapis, unnamed sp. nov.) that is slightly larger and much more robust than previously known Cambay Shale primates. Its anatomy most closely resembles that of Eocene adapoids, and the dental formula is the same as in A. cambayensis. A femur and calcaneus are tentatively allocated to the same taxon. Although the dentition is unknown, exquisite preservation of the dentary of cf. Asiadapis sp. nov. enables an assessment of masticatory musculature, function, and gape adaptations, as well as comparison with an equally well-preserved dentary of the asiadapid Marcgodinot...
The oldest primates of modern aspect (euprimates) appear abruptly on the Holarctic continents dur... more The oldest primates of modern aspect (euprimates) appear abruptly on the Holarctic continents during a brief episode of global warming known as the Paleocene-Eocene Thermal Maximum, at the beginning of the Eocene (∼56 Ma). When they first appear in the fossil record, they are already divided into two distinct clades, Adapoidea (basal members of Strepsirrhini, which includes extant lemurs, lorises, and bushbabies) and Omomyidae (basal Haplorhini, which comprises living tarsiers, monkeys, and apes). Both groups have recently been discovered in the early Eocene Cambay Shale Formation of Vastan lignite mine, Gujarat, India, where they are known mainly from teeth and jaws. The Vastan fossils are dated at ∼54.5 Myr based on associated dinoflagellates and isotope stratigraphy. Here, we describe new, exquisitely preserved limb bones of these Indian primates that reveal more primitive postcranial characteristics than have been previously documented for either clade, and differences between t...
ABSTRACT A new subadult partial skeleton of a pantolestid is reported from the late early Eocene ... more ABSTRACT A new subadult partial skeleton of a pantolestid is reported from the late early Eocene Fossil Butte Member of the Green River Formation. Although the specimen displays a full permanent dentition, the presence of unfused elbow epiphyses (typically the first epiphyses to close), together with a short skull, shallow dentaries, and incompletely erupted third molars, indicates that it was a young juvenile. This adds to evidence that pantolestids had relatively early eruption of permanent premolars and late epiphyseal closure. Based on molar size and morphology, including presence of a well-developed paraconid, the specimen is attributed to Palaeosinopa didelphoides. Despite differences in skeletal size and robustness among the three known Fossil Butte pantolestid skeletons, all of which are skeletally subadult, similarity in molar size (and morphology, to the extent that it is visible) suggests that the three skeletons represent three growth stages of P. didelphoides. If this interpretation is correct, it has implications for recognition of fossil species based on such traits as jaw depth, presence/absence of diastemata, and relative robustness of skeletal features.
Species-level diversity and evolution of Palaeosinopa from the Willwood Formation of the Bighorn ... more Species-level diversity and evolution of Palaeosinopa from the Willwood Formation of the Bighorn Basin is reassessed based on substantial new material from the Bighorn, Powder River, and Wind River basins. We recognize three species of Palaeosinopa in the Willwood Formation of the Bighorn Basin: P. lutreola, P. incerta, and P. veterrima. The late Wasatchian species P. didelphoides is not present in the Bighorn Basin. The Willwood species can be differentiated based only on size. P. veterrima is the most common and wide-ranging species and is the most variable in size and morphology: the stratigraphically lowest individuals are smaller, with narrower, more crestiform lower molars; whereas the highest are larger, with wider, more bunodont teeth. Although it could be argued that these represent distinct species, we demonstrate that this morphological evolution occurred as the gradual and mosaic accumulation of features, suggesting in situ anagenetic evolution. The two smaller species a...
The subfamily Anaptomorphinae contains the oldest and most generalized members of the tarsier-lik... more The subfamily Anaptomorphinae contains the oldest and most generalized members of the tarsier-like primates and is the basal group of the extinct family Omomyidae. The best and most continuous record of anaptomorphine history is from rocks of early Eocene (Wasatchian) age in the Bighorn Basin of northwest Wyoming where eight genera and 14 species are recognized. Three of these species are new (Teilhardina crassidens, Tetonius matthewi, Absarokius metoecus), and four other new species are described from elsewhere (Tetonius mckennai, Absarokius gazini, A. australis, Strigorhysis huerfanensis). Teilhardina tenuicula and Absarokius nocerai are new combined forms. Absarokius noctivagus is considered to be a synonym of A. abbotti, and Mckennamorphus is a synonym of Pseudotetonius.The evolution of dental characters in three principal morphologic clades of anaptomorphines from the Bighorn Basin is documented with the aid of numerous new specimens (75% of the sample is new) and with precise ...
... 607997 Daniela C. Kalthoff a , Kenneth D. Rose b & Wighart Von Koenigswald c pages 1303-1... more ... 607997 Daniela C. Kalthoff a , Kenneth D. Rose b & Wighart Von Koenigswald c pages 1303-1313. ... Fungal hyphae usually have a diameter between 3 and 10 μm (pers. comm., M. Wedin, February 2011). In addition, we did not find structures resembling spores or fruit bodies. ...
A new genus and species of palaeanodont, Arcticanodon dawsonae, is based on a single lower jaw fr... more A new genus and species of palaeanodont, Arcticanodon dawsonae, is based on a single lower jaw fragment from lower Eocene (Wasatchian) strata of the Margaret Formation, Eureka Sound Group, on central Ellesmere Island, Nunavut. The new taxon is more derived than early Paleocene Escavadodontidae, but lacks derived traits of Metacheiromyidae. It is therefore most similar to primitive epoicotheriids, although the similarities are essentially in plesiomorphic features. Consequently, Arcticanodon dawsonae is classified as Palaeanodonta, incertae sedis, pending discovery of more complete specimens.
Several new fossil specimens from the Cambay Shale Formation at Tadkeshwar Lignite Mine in Gujara... more Several new fossil specimens from the Cambay Shale Formation at Tadkeshwar Lignite Mine in Gujarat document the presence of two previously unknown early Eocene primate species from India. A new species of Asiadapis is named based on a jaw fragment preserving premolars similar in morphology to those of A. cambayensis but substantially larger. Also described is an exceptionally preserved edentulous dentary (designated cf. Asiadapis, unnamed sp. nov.) that is slightly larger and much more robust than previously known Cambay Shale primates. Its anatomy most closely resembles that of Eocene adapoids, and the dental formula is the same as in A. cambayensis. A femur and calcaneus are tentatively allocated to the same taxon. Although the dentition is unknown, exquisite preservation of the dentary of cf. Asiadapis sp. nov. enables an assessment of masticatory musculature, function, and gape adaptations, as well as comparison with an equally well-preserved dentary of the asiadapid Marcgodinot...
The oldest primates of modern aspect (euprimates) appear abruptly on the Holarctic continents dur... more The oldest primates of modern aspect (euprimates) appear abruptly on the Holarctic continents during a brief episode of global warming known as the Paleocene-Eocene Thermal Maximum, at the beginning of the Eocene (∼56 Ma). When they first appear in the fossil record, they are already divided into two distinct clades, Adapoidea (basal members of Strepsirrhini, which includes extant lemurs, lorises, and bushbabies) and Omomyidae (basal Haplorhini, which comprises living tarsiers, monkeys, and apes). Both groups have recently been discovered in the early Eocene Cambay Shale Formation of Vastan lignite mine, Gujarat, India, where they are known mainly from teeth and jaws. The Vastan fossils are dated at ∼54.5 Myr based on associated dinoflagellates and isotope stratigraphy. Here, we describe new, exquisitely preserved limb bones of these Indian primates that reveal more primitive postcranial characteristics than have been previously documented for either clade, and differences between t...
ABSTRACT A new subadult partial skeleton of a pantolestid is reported from the late early Eocene ... more ABSTRACT A new subadult partial skeleton of a pantolestid is reported from the late early Eocene Fossil Butte Member of the Green River Formation. Although the specimen displays a full permanent dentition, the presence of unfused elbow epiphyses (typically the first epiphyses to close), together with a short skull, shallow dentaries, and incompletely erupted third molars, indicates that it was a young juvenile. This adds to evidence that pantolestids had relatively early eruption of permanent premolars and late epiphyseal closure. Based on molar size and morphology, including presence of a well-developed paraconid, the specimen is attributed to Palaeosinopa didelphoides. Despite differences in skeletal size and robustness among the three known Fossil Butte pantolestid skeletons, all of which are skeletally subadult, similarity in molar size (and morphology, to the extent that it is visible) suggests that the three skeletons represent three growth stages of P. didelphoides. If this interpretation is correct, it has implications for recognition of fossil species based on such traits as jaw depth, presence/absence of diastemata, and relative robustness of skeletal features.
Species-level diversity and evolution of Palaeosinopa from the Willwood Formation of the Bighorn ... more Species-level diversity and evolution of Palaeosinopa from the Willwood Formation of the Bighorn Basin is reassessed based on substantial new material from the Bighorn, Powder River, and Wind River basins. We recognize three species of Palaeosinopa in the Willwood Formation of the Bighorn Basin: P. lutreola, P. incerta, and P. veterrima. The late Wasatchian species P. didelphoides is not present in the Bighorn Basin. The Willwood species can be differentiated based only on size. P. veterrima is the most common and wide-ranging species and is the most variable in size and morphology: the stratigraphically lowest individuals are smaller, with narrower, more crestiform lower molars; whereas the highest are larger, with wider, more bunodont teeth. Although it could be argued that these represent distinct species, we demonstrate that this morphological evolution occurred as the gradual and mosaic accumulation of features, suggesting in situ anagenetic evolution. The two smaller species a...
The subfamily Anaptomorphinae contains the oldest and most generalized members of the tarsier-lik... more The subfamily Anaptomorphinae contains the oldest and most generalized members of the tarsier-like primates and is the basal group of the extinct family Omomyidae. The best and most continuous record of anaptomorphine history is from rocks of early Eocene (Wasatchian) age in the Bighorn Basin of northwest Wyoming where eight genera and 14 species are recognized. Three of these species are new (Teilhardina crassidens, Tetonius matthewi, Absarokius metoecus), and four other new species are described from elsewhere (Tetonius mckennai, Absarokius gazini, A. australis, Strigorhysis huerfanensis). Teilhardina tenuicula and Absarokius nocerai are new combined forms. Absarokius noctivagus is considered to be a synonym of A. abbotti, and Mckennamorphus is a synonym of Pseudotetonius.The evolution of dental characters in three principal morphologic clades of anaptomorphines from the Bighorn Basin is documented with the aid of numerous new specimens (75% of the sample is new) and with precise ...
... 607997 Daniela C. Kalthoff a , Kenneth D. Rose b & Wighart Von Koenigswald c pages 1303-1... more ... 607997 Daniela C. Kalthoff a , Kenneth D. Rose b & Wighart Von Koenigswald c pages 1303-1313. ... Fungal hyphae usually have a diameter between 3 and 10 μm (pers. comm., M. Wedin, February 2011). In addition, we did not find structures resembling spores or fruit bodies. ...
A new genus and species of palaeanodont, Arcticanodon dawsonae, is based on a single lower jaw fr... more A new genus and species of palaeanodont, Arcticanodon dawsonae, is based on a single lower jaw fragment from lower Eocene (Wasatchian) strata of the Margaret Formation, Eureka Sound Group, on central Ellesmere Island, Nunavut. The new taxon is more derived than early Paleocene Escavadodontidae, but lacks derived traits of Metacheiromyidae. It is therefore most similar to primitive epoicotheriids, although the similarities are essentially in plesiomorphic features. Consequently, Arcticanodon dawsonae is classified as Palaeanodonta, incertae sedis, pending discovery of more complete specimens.
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