vJEW FOSSIL PELOBATID FROGS AND A REVIEW OF [HE GENUS EOPELOBATfS ICHARD ESTES' :ONTENTS abstract 293 atroduction and Acknowledgments 294 .bbreviations 294 he Status of the Genus Eopelobates 295 he Family Assignment of Eopelobates 298 )iscussion of Anatomical Features 298 Frontoparietal-squamosal connection 298 Prootic foramen .-299 Orbitotemporal opening 299 Squamosal angle 299 Ossified sternum 299 Ethmoid 300 chronological Review of Described Eopelobates 304 Eopelobates anthracinus 304 Eopelobates hinschei 306 Eopelobates bayeri 307 Eopelobates grandis 308 Eopelobates sp. 308 )escription of New Material of Eopelobates .. 309 Eopelobates guthriei n. sp. 309 "^Eopelobates sp. 315 he Relationships of Eopelobates 316 Intrageneric classification 322 Adaptation and intrafamihal classification .. 323 he Felobatinae 324 Macropelobates osborni 324 Pelobates 326 Miopelobates robiistus 328 Scaphiopus 328 S. skinneri, n. sp. 328 pecies Removed from the Pelobatidae 333 volution and Zoogeography of tlie Pelobatidae _ 333 ppendix ,337 eferences Cited 338 ^ Department of Biology, Boston University, and luseum of Comparative Zoology, Harvard Uni-ersity. ABSTRACT Eopelobates was a fossil pelobatid frog that lived in North America during the Eocene and early Ohgocene, and may have been present in the Cretaceous as well. In Europe, it extended from middle Eocene through the middle Miocene. In many ways Eopelobates is intermediate between mego-phryine and pelobatine subfamilies, but is retained here in the Megophryinae because of absence of an enlarged prehallux, or spade. Two lines may be distinguished within the genus: a primitive, short-skulled group composed of the North American E. guthriei n. sp. and E. grandis, with the European E. anthracinus probably included here as well, and a long-skulled European lineage composed of E. hinschei (n. comb.) and E. bayeri. The spadefoot toads were probably de-rived from Eopelobates, and the primitive E. guthriei shows some indications of spadefoot relationship. The earliest true spadefoot was Scaphiopus skinneri n. sp., from the early and middle Oligocene of North America. It has some primitive fea-tures but is already close to the modern S. holbrooki. A form close to Pelobates was also present in the early Oligocene of Europe, further implying at least an Eocene divergence of the spadefoots from the megophryines. Tlie early or middle Oligo-cene Macropelobates from Mongolia links Eopelobates and the spadefoots in some Bull. Mus. Comp. Zool., 139(6) : 293-340, May 14, 1970 293
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