Limestone with ammonites
Psiloceras planoribis, Lower Jurassic period. What time is it? If you found this index fossil in a rock, you'd know. The animal was once widespread but quickly became extinct. Only a small percentage of fossils meet these criteria.
Image Number: 97-36383
Catalog Number: 430979
Time Period: Jurassic Period
Loan from Department of Paleobiology