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Mitochondrial genomes reveal the extinct Hippidion as an outgroup to all living equids.

ABSTRACT: Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5 million years ago (Ma) until their extinction approximately 10 000 years ago. The evolutionary origin of the three known Hippidion morphospecies is still disputed. Based on palaeontological data, Hippidion could have diverged from the lineage leading to modern equids before 10 Ma. In contrast, a much later divergence date, with Hippidion nesting within modern equids, was indicated by partial ancient mitochondrial DNA sequences. Here, we characterized eight Hippidion complete mitochondrial genomes at 3.4-386.3-fold coverage using target-enrichment capture and next-generation sequencing. Our dataset reveals that the two morphospecies sequenced (H. saldiasi and H. principale) formed a monophyletic clade, basal to extant and extinct Equus lineages. This contrasts with previous genetic analyses and supports Hippidion as a distinct genus, in agreement with palaeontological models. We date the Hippidion split from Equus at 5.6-6.5 Ma, suggesting an early divergence in North America prior to the colonization of South America, after the formation of the Panamanian Isthmus 3.5 Ma and the Great American Biotic Interchange.

SUBMITTER: Der Sarkissian C

PROVIDER: S-EPMC4387498 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature

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Mitochondrial genomes reveal the extinct Hippidion as an outgroup to all living equids.

Der Sarkissian Clio C Vilstrup Julia T JT Schubert Mikkel M Seguin-Orlando Andaine A Eme David D Weinstock Jacobo J Alberdi Maria Teresa MT Martin Fabiana F Lopez Patricio M PM Prado Jose L JL Prieto Alfredo A Douady Christophe J CJ Stafford Tom W TW Willerslev Eske E Orlando Ludovic L

Biology letters 20150301 3

Hippidions were equids with very distinctive anatomical features. They lived in South America 2.5 million years ago (Ma) until their extinction approximately 10 000 years ago. The evolutionary origin of the three known Hippidion morphospecies is still disputed. Based on palaeontological data, Hippidion could have diverged from the lineage leading to modern equids before 10 Ma. In contrast, a much later divergence date, with Hippidion nesting within modern equids, was indicated by partial ancient ...[more]

PMID: 25762573

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Mitochondrial genomes reveal the extinct Hippidion as an outgroup to all living equids.

Publications

Mitochondrial genomes reveal the extinct Hippidion as an outgroup to all living equids.

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