Paleontology in Texas
During the early Paleozoic era Texas was covered by a sea that would later be home to creatures like brachiopods, cephalopods, graptolites, and trilobites.
Evidence indicates that during the late Carboniferous the state was home to marine life, land plants and early reptiles.
During the Early Cretaceous local large sauropods and theropods left a great abundance of footprints.
Later in the Cretaceous, the state was covered by the Western Interior Seaway and home to creatures like mosasaurs, plesiosaurs, and few icthyosaurs.
Early Cenozoic Texas still contained areas covered in seawater where invertebrates and sharks lived.
On land the state would come to be home to creatures like glyptodonts, mammoths, mastodons, saber-toothed cats, giant ground sloths, titanotheres, uintatheres, and dire wolves.
Pleurocoelus was the Texas state dinosaur from 1997 to 2009, when it was replaced by Sauroposeidon (Paluxysaurus jonesi) after the Texan fossils once referred to the former species were reclassified to a new genus.
[7] The graptolites were preserved in the Ordovician deposits of western Texas, especially some of the stratigraphic units of the Trans-Pecos region.
[4] Known life of Devonian Texas includes brachiopods, bryozoans, conodonts, corals, gastropods, radiolarians and trilobites.
[6] Like the state's Devonian rocks, those of Early Carboniferous age are buried below the surface and inaccessible apart from core drilling.
Contemporary bryozoan and gastropod fossils were preserved in the Hueco Mountains of the Trans-Pecos Region, but are less common.
[4] Texas had a fauna including algae, brachiopods, corals, crinoids, fusulinids, gastropods, and pelecypods during the Pennsylvanian epoch.
[6] Plant fossils were preserved in abundance in the Llano Uplift, north-central, and Trans Pecos Texas.
Author Marian Murray described the region as "one of the finest collecting areas in the world for marine life".
Seymouria, a twenty inch long transitional form documenting the origin of reptiles was preserved in the Permian sediments of Baylor County.
[10] During the middle Permian, Texas was hot with dry and wet seasons attested to by playa lake deposits.
[4] Triassic life in Texas also included plants and invertebrates, although their fossils tend to be poorly preserved.
[6] Triassic fossils were preserved in areas of western Texas like the Glass Mountains as well as the High Plains.
Cretaceous vertebrate life of Texas included amphibians, birds, dinosaurs, fish, and reptiles.
Fossils include mostly teeth, vertebrae, and scales, although sometimes well preserved skeletons are found in the Austin Chalk member.
[6] During the late Albian, from about 115 to 110 million years ago sauropods and theropods left many footprints in the sediments that would later come to compose the Glen Rose Formation.
[10] Fossils of this age from the Gulf Coast and western part of the state included the remains of creatures like bison, mammoths, and mastodons.
[4] Other Cenozoic mammals of Texas included glyptodonts, mammoths, mastodons, saber teeth, giant ground sloths, titanotheres, uintatheres, and dire wolves.
[1] In 1938, Barnum Brown of the American Museum of Natural History sent Roland T. Bird to Texas in search of dinosaur footprints uncovered by local moonshiners.
[21] At the town of Glen Rose he noticed a medium-sized footprint left by a carnivorous dinosaur in a limestone block forming part of the Somervell County courthouse's bandstand.
Local residents guided him to yet further carnivorous dinosaur tracks preserved in situ along the Paluxy River.
[23] In 1940, Bird resumed his Texas fieldwork with the help of paleontologists from the Survey and labor employed by the Works Progress Administration.
[26] In 1964 Bob Slaughter found two genera of mosasaurs south of Dallas as well as Miocene and Pleistocene fossils from the Livingston Reservoir basin.
[10] In 1994, Bill Sarjeant and Wann Langston published a monograph documenting fossil footprints laid down in the volcanic ash of the Vieja Group 36 to 38 million years ago during the late Eocene.
This monograph was the culmination of almost twenty years of research and its subject the most spectacular known Tertiary-aged fossil tracksite in the western United States.
