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Horned Toad Hills fauna:
MAY ET AL.

Plain-Language &
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Abstract

Introduction

Geologic Setting

Horned Toad Formation

Mammalian Paleontology

Systematic Paleontology

Conclusions

Acknowledgements

References

 

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Geology and mammalian paleontology of the Horned Toad Hills, Mojave Desert, California, USA

Steven R. May, Michael O. Woodburne, Everett H. Lindsay, L. Barry Albright,
Andrei Sarna-Wojcicki, Elmira Wan, and David B. Wahl

ABSTRACT

The Horned Toad Formation includes five lithostratigraphic members that record alluvial fan, fluvial, lake margin, and lacustrine deposition within a relatively small basin just south of the active Garlock fault during the late Miocene to early Pliocene. These sediments experienced northwest-southeast contractional deformation during the Pliocene-Pleistocene associated with basement-involved reverse faults. Member Two of the Horned Toad Formation has yielded 24 taxa of fossil mammals, referred to as the Warren Local Fauna, including Cryptotis sp., cf. Scapanus, Hypolagus vetus, Hypolagus edensis, ?Spermophilus sp., Prothomomys warrenensis n. gen., n. sp., Perognathus sp., Repomys gustelyi, Postcopemys valensis, Peromyscus sp. A, Peromyscus sp. B, Jacobsomys dailyi n. sp., Borophagus cf. B. secundus, cf. Agriotherium, Machairodus sp. cf. M. coloradensis, Rhynchotherium sp. cf. R. edensis, Pliomastodon vexillarius, Dinohippus edensis, Teleoceras sp. cf. T. fossiger, cf. Prosthennops, Megatylopus sp. cf. M. matthewi, Hemiauchenia vera, Camelidae gen. et. sp. indet., and the antilocaprid cf. Sphenophalos. The majority of fossil localities are confined to a 20 m thick stratigraphic interval within a reversed polarity magnetozone. The fauna demonstrates affinity with other late Hemphillian faunas from California, Nevada, Nebraska, Texas, and Mexico. The Lawlor Tuff, dated elsewhere in California at 4.83 ± 0.04 Ma and geochemically identified in the Horned Toad Formation, overlies most of the fossil mammal localities. Magnetic polarity data are correlated with Chrons 3n.3r, 3n.3n, and 3n.2r, suggesting an age of approximately 5.0 - 4.6 Ma. These constraints indicate an age for the late Hemphillian Warren Local Fauna of 4.85 - 5.0 Ma.

Steven R. May. ExxonMobil Upstream Research, P.O. Box 2189, Houston, Texas 77252-2189, USA.
Michael O. Woodburne. Museum of Northern Arizona, 3101 N. Ft. Valley Rd. Flagstaff, Arizona 86001, USA
Everett H. Lindsay. University of Arizona, Department of Geosciences, Gould-Simpson Building #77, 1040 E 4th St., Tucson, Arizona 85721, USA
L. Barry Albright, University of North Florida, Jacksonville, Florida 32224, USA
Andrei Sarna-Wojcicki. United States Geological Survey, 345 Middlefield Road MS-973, Menlo Park, CA 94025 USA
Elmira Wan. United States Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA
David B. Wahl. United States Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA

KEY WORDS: stratigraphy; magnetostratigraphy; tephrochronology; biostratigraphy; Garlock fault; Hemphillian; new genus; new species

PE Article Number: 14.3.28A
Copyright: Society of Vertebrate Paleontology November 2011
Submission: 15 June 2007. Acceptance: 29 March 2011

 

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Horned Toad Hills fauna
Plain-Language & Multilingual  Abstracts | Abstract | Introduction | Geologic Setting | Horned Toad Formation
Mammalian Paleontology | Systematic Paleontology | Conclusions | Acknowledgments | References
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