Brachyrhizodus wichitaensis Romer, 1942

Occlusal Views

Basal Views

Lateral Views

• Collector:    Keith Minor

• Formation:  Monmouth Group, Mount Laurel Formation

• Location:     Monmouth County, NJ

• This bat ray is commonly and incorrectly placed in the genus Myliobatis, which also ranges back into the late Cretaceous and has been found in the same formations with Brachyrhizodus.  One very distinguishing feature is that Myliobatis has fine regular grooves on the base of the tooth, while Brachyrhizodus has only a few, irregularly occurring basal grooves, as shown above. 

General Info

Synonyms (older names and misidentifications in the literature)

• Bat Rays
• Eagle Rays
• 1942 Brachyrhizodus wichitaensis Romer
• 1967 Rhinoptera sp. Case
• 1967 Myledaphus sp. Case
• 1973 Rhinoptera sp. Case
• 1975 Brachyrhizodus wichitaensis Romer; Cappetta and Case
• 1978 Brachyrhizodus wichitaensis Romer; Cappetta
• 1983 Brachyrhizodus wichitaensis Roemer; Lauginiger and Hartstein
• 1992 Brachyrhizodus (Protorhinoptera) wichitaensis Romer
• 1987 Brachyrhizodus wichitaensis Romer; Cappetta
• 1993 Brachyrhizodus wichitaensis Romer; Welton and Farish

Stratigraphic Occurrence

• Monmouth Group, Navesink Formation of New Jersey
• Monmouth Group, Mount Laurel Formation of New Jersey and Delaware
• Lower Taylor Group, Ozan Formation of North Texas
• Upper Austin Group, Burditt Formation of South Central Texas

Age

• Brachyrhizodus wichitaensis Romer occurs in the early Campanian in Texas (oldest occurrence in the Menabites (Delawarella) delawarensis (Morton) zone).  In New Jersey, it has been reported from latest Campanian-earliest Maastrichtian deposits, and probably ranges down to the same level as the Texas occurrence.

Geographic Occurrence (not an all-inclusive list)

• Monmouth County, NJ
• Travis County, TX

Remarks

       For identification and descriptions, see:

• Cappetta, H.  1987.  Handbook of Paleoichthyology, Volume 3B:  Chondrichthyes II.  Mesozoic and Cenozoic Elasmobranchii.  New York:  Gustav Fischer Verlag.
• Cappetta, H.; Case, G. R.  1975.  Contribution a l'Étude des Sélachiens du Groupe Monmouth (Campanien-Maestrichtian) du New Jersey.  Palaeontographica (A) 151 (1-3), 1-46.