Abstract
Black Mesa in northeastern Arizona exposes sediments of late Cenomanian–Turonian age deposited during the transgressive–regressive Greenhorn cyclothem. These sediments contain a diverse selachian fauna that consists of 21 taxa:Hybodussp.,Ptychodus whipplei, P. decurrens, P.cf.P. mammillaris, Chiloscyllium greeni, Chiloscylliumsp.,Scapanorhynchus raphiodon, Cretodus semiplicatus, Cretolamna appendiculata, C. woodwardi, Cretoxyrhina mantelli, cf.Leptostyraxsp.,Squalicorax falcatus, Rhinobatossp.,Pseudohypolophus mcnultyi, Protoplatyrhina hopiin. sp.,Ischyrhiza schneideri, I. avonicola, Onchopristis dunklei, Ptychotrygon triangularis, P. rubyaen. sp., and five types of dermal denticles. Two selachian assemblages, a nearshore and a deeper water assemblage, are present in this fauna. Though there is some provincialism in North Africa, Europe, and North America during the Greenhorn marine cycle, the wide dispersion of some shark taxa and the great similarities between widely separated selachian faunas are striking.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
