Trinity Group (geologic formation)

Trinity Group Stratigraphic range: late Aptian-early Albian, 115–106 Ma PreЄ Є O S D C P T J K Pg N
Type	Group
Sub-units	Paluxy Formation Glen Rose Formation Twin Mountains Formation
Underlies	Fredericksburg sands
Location
Region	Texas, Arkansas
Country	United States

The Trinity Group is a group (sequence of rock strata) in the Lower Cretaceous lithostratigraphy of Texas, Arkansas, Mississippi, New Mexico, Louisiana and Oklahoma.^[1] It is named for the Trinity River of Texas.

Vertebrate fauna

Crocodylomorphs

Crocodylomorphs reported from the Trinity Group
Genus	Species	Location	Stratigraphic position	Material	Notes
Pachycheilosuchus[2]	P. trinquei		Glen Rose Formation		A neosuchian related to Eusuchia. Had procoelous vertebrae.
Paluxysuchus[3]	P. newmani		Twin Mountains Formation		A neosuchian related to Eusuchia

Dinosaurs

Dinosaurs reported from the Trinity Group
Genus	Species	Location	Stratigraphic position	Material	Notes
Acrocanthosaurus	A. atokensis[4]		Twin Mountains Formation		A carcharodontosaurid
Astrophocaudia[5]	A. slaughteri		Paluxy Formation		A member of Somphospondyli
Cedarosaurus[5]	C. weiskopfae		Paluxy Formation		A brachiosaurid
Paluxysaurus[6]	P. jonesi		Twin Mountains Formation		Junior synonym of Sauroposeidon proteles
Sauroposeidon[5][6]	S. proteles		Twin Mountains Formation		A member of Somphospondyli
Tenontosaurus	T. dossi[7]		Twin Mountains Formation		An iguanodont
Unnamed ornithopod[8]			Twin Mountains Formation		A basal ornithopod

Pterosaurs

Pterosaurs reported from the Trinity Group
Genus	Species	Location	Stratigraphic position	Material	Notes
Radiodactylus[9]	R. langstoni		Glen Rose Formation		An azhdarchoid pterosaur

References

1. "Geologic Unit: Trinity". National Geologic Map Database. USGS. Retrieved 31 May 2014.
2. Rogers, 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.
3. Adams, 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. edit
4. Harris, 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.
5. D'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.
6. Rose, 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)
7. Winkler, 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.
8. Winkler, 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.
9. Andres, B.; Myers, T. S. (2013). "Lone Star Pterosaurs". Earth and Environmental Science Transactions of the Royal Society of Edinburgh: 1. doi:10.1017/S1755691013000303. edit