Mortoniceras sp. ammonite from the Duck Creek formation of Texas

Before I started on my adventure in Oklahoma I landed in Dallas and drove north to a site that a good friend had suggested I visit. It was a creek that exposed the Duck Creek formation (Cretaceous, Albian stage) in a couple of spots. Having never collected in Texas before, but seeing plenty of field reports from those who had, I knew the Duck Creek formation should produce some nice fossils. I was not wrong. I found four specimens of the ammonite Mortoniceras sp. washed out in the creek bed. Mortoniceras can be identified by the prominent ribbing along the shell and strong rostrum. There are a couple of species of Mortoniceras and I'm not good enough to tell them apart so I will keep these labelled as Mortoniceras sp.

Specimen #1

Specimen #2