SYSTEMATIC PALEONTOLOGY

Etymology. The genus refers to the nearby town of Paluxy, Texas, and the Paluxy River, which flows through this region.

Type and Only Known Species. Paluxysaurus jonesi, sp. nov.

Diagnosis. As for the species.

Etymology. The species is named in honor of William R. (Bill) Jones, who for nearly two decades has graciously allowed the excavation of these important fossils on his land.

Holotype. FWMSH 93B-10-18, an associated left maxilla and nasal and teeth.

Referred Specimens. Associated partial skeletons and isolated bones from at least four different individuals from a single locality that includes: isolated teeth (FWMSH 93B-10-5, FWMSH 93B-10-6, FWMSH 93B-10-33, FWMSH 93B-10-40, FWMSH 93B-10-49, FWMSH 93B-10-50), a series of seven cervical vertebrae (FWMSH 93B-10-[28-32]) and two isolated cervical vertebrae and cervical rib fragments (FWMSH 93B-10-8, FWMSH 93B-10-19); 13 dorsal vertebrae (FWMSH 93B-10-9, FWMSH 93B-10-11, FWMSH 93B-10-13, FWMSH 93B-10-27, FWMSH 93B-10-48, TMM 42488); more than 30 caudal vertebrae (FWMSH 93B-10-12, FWMSH 93B-10-14, FWMSH 93B-10-17, FWMSH 93B-10-21, FWMSH 93B-10-37, FWMSH 93B-10-38, FWMSH 93B-10-[41-44], TMM 42488); four chevrons (FWMSH 93B-10-4, TMM 42488); several dorsal rib fragements (FWMSH 93B-10-13, FWMSH 93B-10-20, FWMSH 93B-10-23); one fused scapulocoracoid (TMM 42488); one scapula (FWMSH 93B-10-24); two coracoids (FWMSH 93B-10-34, FWMSH 93B-10-39); one sternal plate (FWMSH 93B-10-24); four humeri (FWMSH 93B-10-2, FWMSH 93B-10-7, TMM 42488); one ulna (FWMSH 93B-10-7); two radii (FWMSH 93B-10-7, FWMSH 93B-10-36); eight metacarpals (FWMSH 93B-10-1, FWMSH 93B-10-10, FWMSH 93B-10-22, FWMSH 93B-10-36, FWMSH 93B-10-47); two ilia (FWMSH 93B-10-27); five pubes (FWMSH 93B-10-27, FWMSH 93B-10-35, FWMSH 93B-10-51, TMM 42488); five ischia (FWMSH 93B-10-27, FWMSH 93B-10-35, FWMSH 93B-10-51, TMM 42488); six femora (FWMSH 93B-10-3, FWMSH 93B-10-7, FWMSH 93B-10-25, FWMSH 93B-10-27, TMM 42488); four tibiae (FWMSH 93B-10-15, FWMSH 93B-10-45, FWMSH 93B-10-46, TMM 42488); two fibulae (FWMSH 93B-10-15, FWMSH 93B-10-25); and three metatarsals (FWMSH 93B-10-16, FWMSH 93B-10-26). A number of other elements were provisionally identified in the field but have not yet been prepared.

Diagnosis. Paluxysaurus jonesi can be diagnosed based on the following characteristics exhibited by the holotype and referred specimens: broad nasal process of the maxilla; strong lateral curvature of the premaxillary process of the nasal; differs from Brachiosaurus brancai in having a shorter, non-arching premaxillary process of the nasal and a more pronounced lacrimal process of the maxilla; differs from Pleurocoelus sp. in the shape of the caudoventral margin of the maxilla, the shape of the distal scapular blade, and the shape of the proximal condyle of the tibia; differs from Euhelopus zdanskyi in that the nasal process of the maxilla rises from the middle of the bone; distinguished from Brachiosaurus brancai by a distinct intrapostzygapophyseal lamina (tpol) on cervical neural arches; deep postspinal fossa on caudal saurface of cervical neural arches; accessory laminae on dorsal neural arches; dorsal vertebrae that lack a postspinal lamina; mid-caudal centra articular faces angle cranially; cranial and mid-caudal neural arches with intraprezygapophyseal laminae (tprl) that form, with the spinoprezygapophyseal laminae (sprl), a prespinal fossa above the neural canal; transversely expanded cranial and mid-caudal neural spines; distal scapular blade broadly expanded on both acromial and glenoid sides; craniocaudally compressed femoral shaft. It also retains the following plesiomorphies: dorsal neural spines tapering, not flaring, distally; a long pubis relative to the length of the pubioischial articular surface; tibial proximal condyle expanded craniocaudally.

Locality and Age. W.W. Jones Ranch, SMU Locality 282 (FWMSH 93B-10), Hood County, Texas, south-southwest of the town of Tolar. The bone-bed occurs in the Twin Mountains Formation of the Trinity Group and is of late Aptian or earliest Albian age (see above).