#invertbrate

Climactichnites wilsoni

This pair of tracks is a type of trace fossil called Climactichnites wilsoni. That’s the name of the trace fossil, not the name of the organism that made them, as fossils of the organisms have yet to be discovered. Since there are no body fossils of the organism that made these tracks, it is thought that they may have been mostly soft bodied. One possibility is that they were muscular animals that moved along a single trail using muscles or flaps on their lower side, somewhat like large slugs. They are also commonly found associated with fossil remnants of microbial mats, suggesting that microbial mats might have covered these tracks and helped with their preservation.

These fossils are uniformly found in association with sedimentary structures in sand such as ripple marks, which are produced in near-shore or beach environments. They occur in rocks from Eastern North America of Cambrian Age, over 500 million years ago. These trails therefore represent perhaps the first clear example in the fossil record of animal life beginning to move out of the ocean and onto land.

-JBB

FossilFriday

Image credit: Mike Beauregard https://flic.kr/p/P2jiKp

Celebrate the holiday season with the “snowflakes” of prehistory gift wrap. Sea lilies are among the most common fossils found across the world. While crinoid crowns remain elusive, their separated stalks are found as unique and alluring coin-like discs. This is our first item on Society6 with more to come! Not available on the main shop.

sulc.us/wrap