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1	Locomotory Adaptations in Entoptychine Gophers (Rodentia: Geomyidae) and the Mosaic Evolution of Fossoriality Calede, Jonathan J.M., Samuels, Joshua X., Chen, Meng 01 June 2019 (has links) Pocket gophers (family Geomyidae) are the dominant burrowing rodents in North America today. Their fossil record is also incredibly rich; in particular, entoptychine gophers, a diverse extinct subfamily of the Geomyidae, are known from countless teeth and jaws from Oligocene and Miocene-aged deposits of the western United States and Mexico. Their postcranial remains, however, are much rarer and little studied. Yet, they offer the opportunity to investigate the locomotion of fossil gophers, shed light on the evolution of fossoriality, and enable ecomorphological comparisons with contemporaneous rodents. We present herein a quantitative study of the cranial and postcranial remains of eight different species of entoptychine gophers as well as many contemporary rodent species. We find a range of burrowing capabilities within Entoptychinae, including semifossorial scratch-digging animals and fossorial taxa with cranial adaptations to burrowing. Our results suggest the repeated evolution of chisel-tooth digging across genera. Comparisons between entoptychine gophers and contemporaneous rodent taxa show little ecomorphological overlap and suggest that the succession of burrowing rodent taxa on the landscape may have had more to do with habitat partitioning than competition. burrowing Castoridae ecomorphology functional morphology Heteromyidae resource partitioning Geosciences
2	Aplodontid, sciurid, castorid, zapodid and geomyoid rodents of the Rodent Hill locality, Cypress Hills formation, southwest Saskatchewan Bell, Sean Daniel 23 December 2004 The Rodent Hill Locality is a fossil-bearing site that is part of the Cypress Hills Formation, and is located roughly 15 km northwest of the town of Eastend, Saskatchewan. A number of fossil mammal and other vertebrate taxa are present at Rodent Hill; the primary objective of this project was to identify the fossil rodents of the families Sciuridae, Aplodontidae, Castoridae, Heliscomyidae, Heteromyidae, Florentiamyidae and Zapodidae. These taxa were correlated with rodents from other North American faunas to establish the age of the Rodent Hill Locality. <p>The species Haplomys cf. H. liolophus, Dakotallomys cf. D. pelycomyoides, Kirkomys milleri, Proheteromys nebraskensis, Agnotocastor cf. A. praetereadens, and possibly Cedromus cf. C. wilsoni support the Whitneyan age designation of the Rodent Hill Locality. Taxa that are described from Rodent Hill that are better known from earlier-age sites include Heliscomys vetus and H. hatcheri, Ecclesimus sp. and Oligotheriomys sp. Taxa that are younger than Whitneyan but have been recovered at Rodent Hill include Parallomys sp., Plesiosminthus sp., Protospermophilus sp., and Nototamias sp. Two new species in the genus Sciurion, and one new species in the genus Pseudallomys are described, and a new species of Heliscomys is identified but not formally named. <p>The rodents from the Rodent Hill Locality support the Whitneyan age assignment of the site. This is based on the presence of Whitneyan taxa, and the in situ co-occurrence of older and younger taxa within the site. Dakotallomys Pseudallomys Agnotocastor Oligotheriomys Palaeocastorinae Geomyoidea Heliscomyidae Heliscomys Heliscomys vetus Heliscomys hatcheri Syphyriomys Florentiamyidae Kirkomys Kirkomys milleri Ecclesimus Heteromyidae Proheteromys Proheteromys nebraskensis Sciuridae Parallomys Sciurion Castoridae Nototamias Protospermophilus Haplomys Campestrallomys Prosciurus Aplodontidae Cedromus Plesiosminthus Zapodidae North America Oligocene Whitneyan
3	Aplodontid, sciurid, castorid, zapodid and geomyoid rodents of the Rodent Hill locality, Cypress Hills formation, southwest Saskatchewan Bell, Sean Daniel 23 December 2004 (has links) The Rodent Hill Locality is a fossil-bearing site that is part of the Cypress Hills Formation, and is located roughly 15 km northwest of the town of Eastend, Saskatchewan. A number of fossil mammal and other vertebrate taxa are present at Rodent Hill; the primary objective of this project was to identify the fossil rodents of the families Sciuridae, Aplodontidae, Castoridae, Heliscomyidae, Heteromyidae, Florentiamyidae and Zapodidae. These taxa were correlated with rodents from other North American faunas to establish the age of the Rodent Hill Locality. <p>The species Haplomys cf. H. liolophus, Dakotallomys cf. D. pelycomyoides, Kirkomys milleri, Proheteromys nebraskensis, Agnotocastor cf. A. praetereadens, and possibly Cedromus cf. C. wilsoni support the Whitneyan age designation of the Rodent Hill Locality. Taxa that are described from Rodent Hill that are better known from earlier-age sites include Heliscomys vetus and H. hatcheri, Ecclesimus sp. and Oligotheriomys sp. Taxa that are younger than Whitneyan but have been recovered at Rodent Hill include Parallomys sp., Plesiosminthus sp., Protospermophilus sp., and Nototamias sp. Two new species in the genus Sciurion, and one new species in the genus Pseudallomys are described, and a new species of Heliscomys is identified but not formally named. <p>The rodents from the Rodent Hill Locality support the Whitneyan age assignment of the site. This is based on the presence of Whitneyan taxa, and the in situ co-occurrence of older and younger taxa within the site. Dakotallomys Pseudallomys Agnotocastor Oligotheriomys Palaeocastorinae Geomyoidea Heliscomyidae Heliscomys Heliscomys vetus Heliscomys hatcheri Syphyriomys Florentiamyidae Kirkomys Kirkomys milleri Ecclesimus Heteromyidae Proheteromys Proheteromys nebraskensis Sciuridae Parallomys Sciurion Castoridae Nototamias Protospermophilus Haplomys Campestrallomys Prosciurus Aplodontidae Cedromus Plesiosminthus Zapodidae North America Oligocene Whitneyan

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