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Forgotten Crocodile from the Kirtland Formation, San Juan Basin, New

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Forgotten Crocodile from the Kirtland Formation, San Juan Basin, New posed that the narial cavities of Para- Wima1l- saurolophuswere vocal resonating chambers' Goniopholiskirtlandicus Apparently included with this material shippedto Wiman was a partial skull that lromthe Wiman describedas a new speciesof croc- forgottencrocodile odile, Goniopholis kirtlandicus. Wiman publisheda descriptionof G. kirtlandicusin Basin, 1932in the Bulletin of the GeologicalInstitute KirtlandFormation, San Juan of IJppsala. Notice of this specieshas not appearedin any Americanpublication. Klilin NewMexico (1955)presented a descriptionand illustration of the speciesin French, but essentially repeatedWiman (1932). byDonald L. Wolberg, Vertebrate Paleontologist, NewMexico Bureau of lVlinesand Mineral Resources, Socorro, NIM Localityinformation for Crocodilian bone, armor, and teeth are Goni o p holi s kir t landicus common in Late Cretaceous and Early Ter- The skeletalmaterial referred to Gonio- tiary deposits of the San Juan Basin and pholis kirtlandicus includesmost of the right elsewhere.In the Fruitland and Kirtland For- side of a skull, a squamosalfragment, and a mations of the San Juan Basin, Late Creta- portion of dorsal plate. The referral of the ceous crocodiles were important carnivores of dorsalplate probably represents an interpreta- the reconstructed stream and stream-bank tion of the proximity of the material when community (Wolberg, 1980). In the Kirtland found. Figs. I and 2, taken from Wiman Formation, a mesosuchian crocodile, Gonio- (1932),illustrate this material. pholis kirtlandicus, discovered by Charles H. Wiman(1932, p. 181)recorded the follow- Sternbergin the early 1920'sand not described ing locality data, provided by Sternberg: until 1932 by Carl Wiman, has been all but of Crocodile.Kirtland shalesa 100feet ignored since its description and referral. "Skull below the Ojo Alamo Sandstonein the blue Specimensreferred to other crocodilian genera cley. Barrel Springs Wash, 2.5 miles S. may actually represent G. kirtlandicus or Trading Store(Post), Ojo Alamo Wash New other mesosuchians. A better understanding Mexico.CH. H. STERNBERG1921." In his of the distribution of G. kirtlandicus may aid descriptionof the specimen,Wiman notesthat in determining.age relationships in Late the bones are light gray externallybut are Cretaceousdeposits of the San Juan Basin. darker. almost btack ("fast schwarz"), Numerous studies related to Late Creta- "on ceous vertebrate faunal assemblagesof the San Juan Basin frequently mention crocodiles, but usually only in passing. Published work includes Gilmore (1916, 1919, 1935), Bauer (1916),Reeside (1924), Colbert (1950),Powell (1972, 1973), and Wolberg and LeMone (1980). Unpublished reports include Kues and others (1977) and LeMone and others (1977, 1979). Gilmore (1916) reported crocodiles and Brachychampsa sp. from the Kirtland and "crocodiles" from the Ojo Alamo Sandstone. FIGURE l-RecoNsrnucrroN oF DoRSALASPEcT oF Later, in 1919, he reported "crocodiles" from Got'ttopnotts KTRTLANDICUS,approximately % the Fruitland, Kirtland, and Ojo Alamo but size. Abbreviations: Na, external nares; In, in- noted in 1935 that "the Crocodilia and Pisces dentation for pseudo-canine of mandible; Pm' premaxillary; N, nasal; La, are too fragmentary to be of assistance" Mx, maxillary; lacrimal; Pfr, prefrontal; Or, orbit; Por, post- (p. 187). Reeside (1924) lists Crocodylus sp. orbital; Fr, frontal; Fts, superior temporal fossa; and Brachychampsa? sp. for the Kirtland For- Pa, parietal; Sq, squamosal(after Wiman, 1932). mation. Powell (1972, 1973) lists Crocodylus sp. and Brachychampsa? sp. for the Fruitland and Kirtland Formations. Crocodylus sp. and Brachychampsa? sp. are also mentioned by fenestra, a ceratopsian dinosaur found by Kues and others (1977), LeMone and others Sternbergin Kimbeto Wash.Sternberg found (1977, 1979), and Wolberg and LeMone a similar specimenin 1922and sold it to the (1980). Few detailed analyses of crocodilians American Museum of Natural History. Henry have been done, and the Late Cretaceous Fairfield Osborn, the well-known American crocodiles of the San Juan Basin have not paleontologist,published a descriptionof this been adequatelystudied. specimenand named it Pentacerotopsstern- bergii (Osborn,l92l). Early paleontology in San Juan Basin Wiman (1931)published a descriptionof Charles H. Sternberg, a well-known fossil still anotherdinosaur found by Sternbergin collector of the late 1800'sand early 1900's, Parasaurolophustubicen. 1921,the hadrosaur FICURE 2-RrcoNsrnucrtoN oF rHE PALATAL sold a number of reptilian specimenshe col- P. tubicenis characterizedby the development ASeECToF Got'ttoptlotts KIRTLANDICUS,approx- lected in l92l in the San Juan Basin to Carl of a cranialcrest (Lull and Wright, 1942)that imately % size. Abbreviations: Pmn premaxillary; Wiman, paleontologist at the Paleontological may havefunctioned as a visual and acoustical Mx, maxillary; Pal, palatine; Or, orbit; ln, inden- Institute of Uppsala University (Sternberg, displayorgan (Hopson, 1975).Wiman sug- tation for pseudo-canine of mandible (redrawn 1932). Wiman (1930) describedPentaceratops gesteda similaridea in his 1931paper and pro- from Wiman, 1932,with modifications)' New Mexico Geology August1980 freshly fracturedsurfaces. He notesthat the On the basis of the observable morphology enclosingmatrix consistsof a yellow-gray, ' of G. kirtlandicus, the species is separable Oio" Alano z fine-grainedsandstone that provedto be very T.P. x' from other members of the genus noted . fr* .^ hardduring preparation. *'."."tivl.q{'lu, \),J-' above. lf additional specimens of G. kirt- The old Ojo Alamo Trading Post was sit- $(9 landicus occur in existing collections, they l->l \ .6 uated along Alamo Wash in SE%NW% sec. 'sl'l should be separable from eusuchians, given 8, T.24 N., R. ll W. at an elevationof j_4i' adequatematerial. ,. -"n*.(, approximately 6,340 ft (Clemens, 1973\. $ ,t Sternberg noted that G" kirtlandicus was Crocodilian phylogeny found approximately2.5 mi south of the The crocodiles belong to the reptilian trading post in Barrel Springs Wash, now subclass, the Archosauria (the "ruling rep- known as De-na-zinWash. Sternbergprob- tiles"), which includes the dominant animals ably overestimatedthe distancesouth of the ' of the Mesozoic Era, the dinosaurs and ptero- trading post. The specimenprobably came ,{' saurs. Along with other members of the sub- from nearthe middle of sec.20, T. 24 N., R. ,lot class, the order Crocodilia originated within 1l W.: a distanceof 2.5 mi south of the !,- a' the order Thecodontia sometime during the tradingpost sitewould haveplaced Sternberg Triassic. The Crocodilia includes five in the extremesouthern portion of sec.20, out 1F' suborders: Protosuchia, Archaeosuchia, of De-na-zinWash (fig. 3). Mesosuchia, Sebecosuchiaand the Eusuchia The stratigraphicdefinitions of the upper- /L' (Romer, 1966). Since their appearanceduring - t mostCretaceous and lowermostTertiary units )da ,, the Triassic (fig. 5) members of Crocodilia in the San Juan Basinhave been discussed at have remained relatively generalized in struc- lengthby Baltz and others(1966), Fassett and ture and have retained many primitive char- Hinds (1971), and Clemens (1973). The acters, except for the development of a boundary between the Kirtland and Ojo specialized palate. The crocodiles have Alamo Formation, long disputedby various adapted to an aquatic environment by authors(Brown, l9l0; Sinclairand Granger, FIGURE 3-Mnp oF rHE oLD Oro AL.c.N,roTneuuc developing a powerful tail for swimming, par- l9l4), lies within the area of the old Ojo Posr enEe, T. 24 N., R. I I W. Sternberg's local- tially webbed feet, and-most importantly-a ity Alamo Trading Post. Fassett and Hinds data for Goniopholis kirtlandicus indicated secondary palate that separatesbreathing and that the specimen came from Barrel Springs Ar- (1971)mapped as Kirtland the areadescribed functions. This last adaptation is royo (now swallowing by Sternberg'sdescription Wiman. De-na-zin Wash), 2.5 mi south of the to Stern- trading post. As can be seenfrom the map, Stern- obviously useful for an animal that takes at berg (1932)seems certain of his stratigraphic berg must have overestimatedthe distance. least part of its food under water. units; moreover, he reports lengthy discus- Modern crocodiles representthe last surviv- sionswith J. B. Reeside.who was also in the ing remnant of the archosaurian branch that field in 1921; Reesideprobably provided DescriptionoI Goniopholiskirtlandicus dominated the Mesozoic world. These recent, Sternberg with stratigraphic information. Wiman (1932)described G. kirtlandicusin still-surviving members of the Eusuchia are Sternberg'sstratigraphy (1932) appears to be detailand suggestedreconstructions for miss- actually a relatively late adaptive radiation coincidentwith interpretationspublished by ing portionsof the skulland palate(figs. I and that first appeared in the Lower Cretaceous Reeside(1924\, and G. kirtlandicus must have 2). He further distinguishedthe morphology and includes two families, the Gavialidae and beenfound in theKirtland Formation(fig. a). of G. kirtlondicus from the other recognized the Crocodylidae. speciesreferred to thegenus. The gavials are presently restricted to the In G. kirtlandicus, the skull is triangular in major rivers of India, Pakistan, and Burma Gents Goniopholis shape(dorsal view) and lessthan twiceas long but earlier in the Cenozoic had a much greater distribution that included North and South Goniopholis was described by Owen on the as wide at the reconstructedbase.
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