The Trinity Group is a group (sequence of rock strata) in the Lower Cretaceous lithostratigraphy of Texas, Arkansas, Mississippi, Louisiana and Oklahoma. It is named for the Trinity River of Texas.
A stratigraphic column at the Mount Bonnell Fault location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group. Upper Cretaceous formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Trinity Group include the Hammett Formation, Cow Creek Formation, Hensel Formation, and Lower and Upper Glen Rose Formation. The Hammett and the lower portion of the Upper Glen Rose act as confining units (or aquitard) for the Middle Trinity Aquifer. The Upper Glen Rose contains the Upper Trinity Aquifer, which appears to have intra-aquifer groundwater flow with the Edwards Aquifer as water levels are at the same elevation.
Vertebrate fauna
Crocodylomorphs Crocodylomorphs reported from the Trinity Group Genus Species Location Stratigraphic position Material NotesPachycheilosuchusRogers, Jack V., II (2003). "Pachycheilosuchus trinquei, a new procoelous crocodyliform from the Lower Cretaceous (Albian) Glen Rose Formation of Texas". Journal of Vertebrate Paleontology 23 (1): 128–145. doi:10.1671/0272-4634(2003)23[128:PTANPC]2.0.CO;2.P. trinqueiGlen Rose FormationA neosuchian related to Eusuchia. Had procoelous vertebrae.PaluxysuchusAdams, T. L. (2013). "A new neosuchian crocodyliform from the Lower Cretaceous (late Aptian) Twin Mountains Formation of North-Central Texas". Journal of Vertebrate Paleontology 33: 85–10. doi:10.1080/02724634.2012.713277. editP. newmaniTwin Mountains FormationA neosuchian related to Eusuchia
Dinosaurs Dinosaurs reported from the Trinity Group Genus Species Location Stratigraphic position Material NotesAcrocanthosaurusA. atokensisHarris, J. D. 1998. A reanalysis of Acrocanthosaurus atokensis, its phylogenetic status, and paleobiogeographic implications, based on a new specimen from Texas. New Mexico Museum of Natural History and Science, Bulletin 13: 1-75.Twin Mountains FormationA carcharodontosauridArkansaurusReBecca K. Hunt; James H. Quinn (2018). "A new ornithomimosaur from the Lower Cretaceous Trinity Group of Arkansas". Journal of Vertebrate Paleontology. Online edition: e1421209. doi:10.1080/02724634.2017.1421209.A. fridayiAn ornithomimosaurAstrophocaudiaD'Emic, M. D. 2013. Revision of the sauropod dinosaurs of the Early Cretaceous Trinity Group, southern USA, with the description of a new genus. Journal of Systematic Palaeontology, 11:707-726.A. slaughteriPaluxy FormationA member of SomphospondyliCedarosaurusC. weiskopfaePaluxy FormationA brachiosauridPaluxysaurusP. jonesiTwin Mountains FormationJunior synonym of Sauroposeidon protelesSauroposeidonRose, P. J., 2007. A new titanosauriform sauropod (Dinosauria: Saurischia) from the Early Cretaceous of Central Texas and its phylogenetic relationships. Palaeontologia Electronica Vol. 10, Issue 2; 8A:65p, 2.6MB; http://palaeo-electronica.org/paleo/2007_2/00063/index.html (PDF: 65 pages)S. protelesTwin Mountains FormationA member of SomphospondyliTenontosaurusT. dossiWinkler, D., P. A. Murry, and L. L. Jacobs. 1997. A new species of Tenontosaurus (Dinosauria, Ornithopoda) from the early Cretaceous of Texas. Journal of Vertebrate Paleontology, 17:330-348.Twin Mountains FormationAn iguanodontConvolosaurusWinkler, D. and P. A. Murry. 1989. Paleoecology and hypsilophodontid behavior at the Proctor Lake dinosaur locality (early Cretaceous) Texas. Geological Society of America, Special Paper 238:55-61.C. marriTwin Mountains FormationA basal ornithopod
Pterosaurs Pterosaurs reported from the Trinity Group Genus Species Location Stratigraphic position Material NotesRadiodactylusAndres, B.; Myers, T. S. (2013). "Lone Star Pterosaurs". Earth and Environmental Science Transactions of the Royal Society of Edinburgh: 1. doi:10.1017/S1755691013000303. editR. langstoniGlen Rose FormationAn azhdarchoid pterosaur
References