Antlers Formation Explained

Antlers Formation
Type:	Geological formation
Period:	Aptian
Age:	Aptian ~
Prilithology:	Mudstone
Otherlithology:	Sandstone
Namedby:	Robert Thomas Hill^[1]
Region:	,

The Antlers Formation is a stratum which ranges from Arkansas through southern Oklahoma into northeastern Texas. The stratum is 150m (490feet) thick consisting of silty to sandy mudstone and fine to coarse grained sandstone that is poorly to moderately sorted. The stratum is cemented with clay and calcium carbonate. In places the sandstone may be conglomeratic or ferruginous (rich in iron oxides).

Based on correlation with the Trinity Group of Texas, the Antlers Formation is estimated to be late Aptian-early Albian. This age range is supported by the presence of two dinosaurs that are also known from the Cloverly Formation, Deinonychus and Tenontosaurus.

Amphibians

Indeterminate frog remains. Possible indeterminate salamander remains.

Fish

References: Cifelli et al. 1999; Wedel et al. 2000, Kielan-Jarorowska and Cifelli 2001; Nydam and Cifelli 2002.

Cartilaginous fish

Chondrichthyans of the Antlers Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Hybodus	Hybodus butleri				Hybodontidae
	?Hybodus sp.
Lissodus	Lissodus anitae				Polyacrodontidae

Ray-finned fish

Possible indeterminate amid remains. Possible indeterminate lepisosteid remains. Possible indeterminate semionotidae remains.

Actinopterygians of the Antlers Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images -->
Gyronchus	Gyronchus dumblei					-->
?Palaeobalistum	?Palaeobalistum sp.

Mammals

Possible indeterminate deltatheroidan material. Indeterminate multituberculate remains. Indeterminate tribosphenidan remains.

Mammals of the Antlers Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images -->
Astroconodon	Astroconodon sp.					-->
Atokatheridium	Atokatheridium boreni
?Paracimexomys	Paracimexomys crossi

Reptiles

Crurotarsans

Possible indeterminate atoposaurid remains. Possible indeterminate goniopholidid remains. Possible indeterminate pholidosaurid remains.

Lepidosaurs

Possible indeterminate scincid remains.

Lepidosaurs of the Antlers Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images -->
Atokasaurus	Atokasaurus metarsiodon					-->
Ptilotodon	Ptilotodon wilsoni

Saurischians

Possible indeterminate bird remains are known from the formation.

Saurischians of the Antlers Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Acrocanthosaurus	Acrocanthosaurus atokensis
Astrodon	Astrodon sp.
Deinonychus	Deinonychus antirrhopus
Sauroposeidon	Sauroposeidon proteles			"[Four] cervical vertebrae."^[2]

Turtles

Turtles of the Antlers Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images -->
?Glyptops	Glyptops sp.					-->
Naomichelys	Naomichelys sp.

See also

• List of dinosaur-bearing rock formations

References

1. Hill. R.T.. Geology of parts of Texas, Indian Territory and Arkansas adjacent to Red River. Bulletin of the Geological Society of America. 1894. 5. 303.
2. "Table 13.1," in Weishampel, et al. (2004). Page 267.

Further reading

• Cifelli, R. Gardner, J.D., Nydam, R.L., and Brinkman, D.L. 1999. Additions to the vertebrate fauna of the Antlers Formation (Lower Cretaceous), southeastern Oklahoma. Oklahoma Geology Notes 57:124-131.
• Nydam, R.L. and R. L. Cifelli. 2002a. Lizards from the Lower Cretaceous (Aptian-Albian) Antlers and Cloverly formations. Journal of Vertebrate Paleontology. 22:286–298.
• Kielan-Jarorowska, Z., and Cifelli, R.L. 2001. Primitive boreosphenidan mammal (?Deltatheroida) from the Early Cretaceous of Oklahoma. Acta Palaeontologica Polonica 46: 377-391.
• Wedel, M.J., Cifelli, R.L., and Sanders, R. K. 2000. Sauroposeidon Proteles, A new sauropod from the Early Cretaceous of Oklahoma. Journal of Vertebrate Paleontology 20:109-114.