The Pennsylvanian Minturn Formation at McCoy, CO is known for its marine invertebrates fossils.  During the Pennsylvanian Period (approx. 300 million years ago), Colorado was closer to the equator.  The area was submerged in the ocean at times resulting in marine invertebrate fossils such as crinoids, brachiopods and shark teeth.  At other times, the area was terrestrial due to fluctuations in sea level.  This resulted in terrestrial plant fossils.  One plant, Walchia, is one of the earliest conifers in North America.  The discoveries shown here represent both of these paleoenvironments.  (See map below.) Brachiopods Crinoid stems (and spine?, lower right) Horn Coral Unidentified plant, possibly early conifer Ernestiodendron filiciforme (See note 1) If you notice any errors in identification, please contact Steve Wagner.      SEE ALL IMAGES FROM TRIP!

Notes & References:

(1) Map by R. Blakey, Northern Ariz. Univ, modified for McCoy by Wayne Itano.
(2) Fossils of McCoy, Colorado, Wayne Itano. (A pictorial guide to the Pennsylvanian fossils of McCoy, Colorado. Reprinted from Trilobite Tales, the newsletter of the Western Interior Paleontological Association, November 2002.