For #fossilfriday, we are very pleased to announce that the following title has been accepted for production: Fossils of the Big Hill Konservat-Lagerstatte: A Remarkable Late Ordovician Paleobiota from Michigan, USA by Ronald C. Meyer & Gerald O. Gunderson.
The authors originally stumbled on to an outcrop that caught their eye while collecting in the Upper Peninsula of Michigan. A portion of this exposure is made up of fine textured dolostone, and is separated by a few layers of dolomitic shale. The geologic setting at this site is close to the Silurian Period, but is actually near the top of the Richmond Group, Late Ordovician period, 445 million years ago. At least three dozen species, many new to science, have been found. The most noteworthy fossils are: a few species of green algae, not easy to find; a possible red/brown alga; a variety of cephalopods in different stages of preservation; a couple large, three dimensional specimens that look like sponges; a large number of inarticulate brachiopods; numerous medusae (multiple species of jellyfish); a carbonized film which has a quilt-like pattern; a rare halloporid bryozoan; and microbial mats that look like elephant skin.
Of special scientific importance was the discovery of all of the three main Chelicerata: horseshoe crabs, the now extinct eurypterids (sea scorpions), and for the first time ever, complete specimens of Chasmataspidida (as shown on the front cover of the book).
It is interesting to note that the eurypterid preservation at times was so good that even the original carapace was preserved. In addition, it is believed there were two distinct species of eurypterid living in the ecosystem.
The new chasmataspidid species has been described as Hoplitaspis hiawathai. It is argued that the large number of specimens, of different sizes, was the result of the creatures gathering in the lagoon to molt together as a protective measure. Consequently, many of the specimens are molts, but a number are spectacular three-dimensional specimens of the actual animal.
The horseshoe crabs are the oldest complete specimens to date and have yet to be described.
The speculation is that the many members of this diverse ecosystem were living in a shallow nearshore lagoon, and a number of other organisms had drifted into this place from deeper water. What’s unique about this discovery is that the majority of Konservat-Lagerstätten are from deep water ecosystems whereas the big Hill is nearshore and consequently forms a unique link to life emerging on land.
We are expecting this title to be released mid 2021.
Here’s a link to the story the discovery story on YouTube:
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