Answer Monday!

credit: Museum of Comparative Zoology, Harvard University I admit, I thought more of you would get the locality! To me “famous locality” plus light sandy color could only be the Solnhofen limestone.

These extremely fine-grained limestone deposits from Germany were formed in warm, calm, shallow, and quite likely anoxic (oxygen-free) lagoons in the late Jurassic (about 155 million years ago). If you remember from earlier fossil posts, shallow anoxic seas are pretty much ideal places for fossilization, and Solnhofen fossils do not disappoint. They are absolutely gorgeous, and the preservation, especially of soft tissues, is remarkable. The Solnhofen is most famous for preserving Archaeopteryx in exquisite detail, but many other types of organisms found their way into these Jurassic lagoons. This critter, for example, is clearly not Archaeopteryx, but rather an extinct arthropod called Mesolimulus walchi. A close cousin to the extant horseshoe crab, M. walchi is best known from the Solnhofen and left behind trackways that kept paleontologists guessing for some time. It wasn’t until a M. walchi was found at the center of a “death spiral” that the trackways’ provenance became clear.

Congratulations to Dan Phelps (with an assist from Dan Coleman), our big winner(s) this week!