Scaphites sp. (semicostatus?) next to smaller confirmed S. semicostatus
North Texas. Atco formation. Upper Coniacian.
Found at a site further to to south than my normal Atco sites. It is larger and just generally more robust than any of my other Scaphites semicostatus specimens.
The smaller S. semicostatus (bottom) came from one of my normal Atco sites.
Compare with the S. semicostatus holotype here: http://www.thefossilforum.com/index.php?/gallery/image/57475-scaphites-semicostatus-holotype/&context=widget