This fossil stingray was found in the ~50 million year old Green River Formation of Wyoming. You might recognize it’s stingray shape, and you’d be right – it is just a fossil relative of modern stingrays! Like the other animals preserved in the Green River Formation, this is an incredibly well-preserved fossil, due in large part to the lack of oxygen in the preservational environment (no oxygen = no scavenging).

I chose this specimen of Heliobatis for one simple reason – it has claspers! You can easily recognize the long spike that is similar to that of modern stingrays, but look for the other two, smaller spikes – those little bony spikes are called claspers. They are the copulatory organs in male chondrichthyans (including sharks and rays). That little anatomical insight allows us to say, beyond the shadow of a doubt, that this Heliobatis was a male.
– Kristi Curry Rogers, Curator of Paleontology