Small bird and mammal tracks from a mid-Cenozoic volcanic province in Southern Colorado: implications for palaeobiology. (2nd January 2022)

• Record Type: Journal Article
• Authors: Lockley, Martin G.; Goodell, Zane; Evaskovich, John; Krall, Angie; Schumacher, Bruce a; Romilio, Anthony
• Is Part Of: Historical biology. Volume 34:Number 1(2022)
• Page Start: 130
• Page End: 140
• Publication Date: 2022-01-02
• Subjects: San juan volcanism -- mammal tracks -- bird tracks; Paleobiology -- Periodicals; Biology -- Periodicals; Evolution -- Periodicals; Paleontology -- Periodicals; Biology -- Periodicals; Paleontology -- Periodicals; Evolution -- Periodicals; 560.5
• DOI: 10.1080/08912963.2021.1903456
• Languages: English
• ISSNs: 0891-2963

Abstract

ABSTRACT: The surprise discovery of two small assemblages of well-preserved, small bird and small mammal tracks in a thin unit of reworked tuff in the mid-Cenozoic volcanic field of southwestern Colorado represents the first significant report of tetrapod tracks in the region. The bird tracks are represented by a new ichnospecies of Avipeda ( A. circumontis ichnosp. nov.), which differs from other Avipeda ichnospecies in representing a trackmaker with a narrower foot and comparatively robust digit traces and digital pads. The mammal tracks which are also well preserved are small (< 1.5 cm long and wide) tetradactyl-pentadactyl and rodent like. They are arguably unique and among the best-preserved small mammal tracks presently known from the Cenozoic, and are here assigned to the new ichnotaxon Musvestigium minutus ichnogen et ichnosp nov. The track-bearing surface represents a very thin unit of reworked tuff sandwiched between massive ignimbrite flows, and therefore represents a localised window into a brief period of biotic activity in local phase of quiescence in a large, active volcanic province.