The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents
Dipodomyine heteromyids (kangaroo rats and mice) are a diverse group of arid-adapted ricochetal rodents of North America. Here, a new genus and species of a large dipodomyine is reported from early Miocene-aged deposits of the John Day Formation in Oregon that represents the earliest record of the s...
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| Format: | Article |
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PeerJ Inc.
2023-03-01
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| Online Access: | https://peerj.com/articles/14693.pdf |
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| author | Joshua X. Samuels Jonathan J.-M. Calede Robert M. Hunt, Jr. |
| author_facet | Joshua X. Samuels Jonathan J.-M. Calede Robert M. Hunt, Jr. |
| author_sort | Joshua X. Samuels |
| collection | DOAJ |
| description | Dipodomyine heteromyids (kangaroo rats and mice) are a diverse group of arid-adapted ricochetal rodents of North America. Here, a new genus and species of a large dipodomyine is reported from early Miocene-aged deposits of the John Day Formation in Oregon that represents the earliest record of the subfamily. The taxon is known from a single specimen consisting of a nearly complete skull, dentary, partial pes, and caudal vertebra. The specimen is characterized by a mosaic of ancestral and highly derived cranial features of heteromyids. Specifically, the dental morphology and some cranial characteristics are similar to early heteromyids, but other aspects of morphology, including the exceptionally inflated auditory bullae, are more similar to known dipodomyines. This specimen was included in a phylogenetic analysis comprising 96 characters and the broadest sampling of living and extinct geomorph rodents of any morphological phylogenetic analysis to date. Results support the monophyly of crown-group Heteromyidae exclusive of Geomyidae and place the new taxon within Dipodomyinae. The new heteromyid is the largest known member of the family. Analyses suggest that large body size evolved several times within Heteromyidae. Overall, the morphology of the new heteromyid supports a mosaic evolution of the open-habitat adaptations that characterize kangaroo rats and mice, with the inflation of the auditory bulla appearing early in the group, and bipedality/ricochetal locomotion appearing later. We hypothesize that cooling and drying conditions in the late Oligocene and early Miocene favored adaptations for life in more open habitats, resulting in increased locomotor specialization in this lineage over time from a terrestrial ancestor. |
| first_indexed | 2024-03-09T04:11:56Z |
| format | Article |
| id | doaj.art-aff3995adb2f456a9621d6a30e5fe83a |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T04:11:56Z |
| publishDate | 2023-03-01 |
| publisher | PeerJ Inc. |
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| spelling | doaj.art-aff3995adb2f456a9621d6a30e5fe83a2023-12-03T13:59:59ZengPeerJ Inc.PeerJ2167-83592023-03-0111e1469310.7717/peerj.14693The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodentsJoshua X. Samuels0Jonathan J.-M. Calede1Robert M. Hunt, Jr.2Department of Geosciences, Don Sundquist Center of Excellence in Paleontology, East Tennessee State University, Johnson City, TN, United States of AmericaDepartment of Evolution, Ecology, and Organismal Biology, Ohio State University—Marion, Marion, OH, United States of AmericaDepartment of Earth and Atmospheric Sciences, University of Nebraska—Lincoln, Lincoln, NE, United States of AmericaDipodomyine heteromyids (kangaroo rats and mice) are a diverse group of arid-adapted ricochetal rodents of North America. Here, a new genus and species of a large dipodomyine is reported from early Miocene-aged deposits of the John Day Formation in Oregon that represents the earliest record of the subfamily. The taxon is known from a single specimen consisting of a nearly complete skull, dentary, partial pes, and caudal vertebra. The specimen is characterized by a mosaic of ancestral and highly derived cranial features of heteromyids. Specifically, the dental morphology and some cranial characteristics are similar to early heteromyids, but other aspects of morphology, including the exceptionally inflated auditory bullae, are more similar to known dipodomyines. This specimen was included in a phylogenetic analysis comprising 96 characters and the broadest sampling of living and extinct geomorph rodents of any morphological phylogenetic analysis to date. Results support the monophyly of crown-group Heteromyidae exclusive of Geomyidae and place the new taxon within Dipodomyinae. The new heteromyid is the largest known member of the family. Analyses suggest that large body size evolved several times within Heteromyidae. Overall, the morphology of the new heteromyid supports a mosaic evolution of the open-habitat adaptations that characterize kangaroo rats and mice, with the inflation of the auditory bulla appearing early in the group, and bipedality/ricochetal locomotion appearing later. We hypothesize that cooling and drying conditions in the late Oligocene and early Miocene favored adaptations for life in more open habitats, resulting in increased locomotor specialization in this lineage over time from a terrestrial ancestor.https://peerj.com/articles/14693.pdfKangaroo ratHeteromyidaeMosaic evolutionGeomorpha |
| spellingShingle | Joshua X. Samuels Jonathan J.-M. Calede Robert M. Hunt, Jr. The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents PeerJ Kangaroo rat Heteromyidae Mosaic evolution Geomorpha |
| title | The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents |
| title_full | The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents |
| title_fullStr | The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents |
| title_full_unstemmed | The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents |
| title_short | The earliest dipodomyine heteromyid in North America and the phylogenetic relationships of geomorph rodents |
| title_sort | earliest dipodomyine heteromyid in north america and the phylogenetic relationships of geomorph rodents |
| topic | Kangaroo rat Heteromyidae Mosaic evolution Geomorpha |
| url | https://peerj.com/articles/14693.pdf |
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