Tuscahoma Formation

The Tuscahoma Formation or Tuscahoma Sand is a geologic formation in Mississippi and Alabama, United States. It preserves fossils dating back to the early Paleogene period, from the Late Paleocene and Early Eocene.^[1] It was primarily deposited in a marine habitat, but one Wasatchian-aged locality near Meridian, Mississippi was deposited in an estuarine habitat that preserves a significant terrestrial vertebrate fauna, known as the "Red Hot local fauna".^[2][3] It preserves one of the most diverse early Eocene mammalian faunas from eastern North America, roughly contemporaneous with the Willwood Formation of Wyoming.^[3][4]

Tuscahoma Formation
Stratigraphic range: Thanetian to earliest Ypresian, 57–55 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Formation
Unit of	Wilcox Group
Sub-units	Bells Landing Member, Greggs Landing Member
Underlies	Bashi Formation
Overlies	Nanafalia Formation
Lithology
Primary	Sandstone
Location
Region	Mississippi, Alabama
Country	United States

Vertebrate paleofauna

Cartilaginous fishes

Based on the Paleobiology Database:^[5]

Cartilaginous fishes of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Abdounia	A. beaugei				A requiem shark.
	A. subulidens
Aetomylaeus	A. dixoni				An eagle ray.
Anomotodon	A. sp.				A goblin shark.
Brachycarcharias	B. mississippiensis				A sand shark, type locality of species.
Carcharias	C. hoperi				A sand shark.
	C. robustus
	C. teretidens
Chaenogaleus	C. affinis				A relative of the hooktooth shark.
Coupatezia	C. woutersi				A stingray of uncertain affinities.
Cretalamna	C. aschersoni				A megatooth shark.
	C. lerichei
Dasyatis	D. jaekeli				A whiptail stingray.
	D. tricuspidatus
Eotorpedo	E. jaekeli				A torpedo ray.
Galeorhinus	G. minor				A relative of the school shark.
	G. ypresiensis
Ginglymostoma	G. subafricanum				A nurse shark.
Hypotodus	H. verticalis				A sand shark.
?Jaekelotodus	J. sp.				A sand shark.
Mustelus	M. rogersi				A smooth-hound.
Nebrius	N. thielensis				A nurse shark.
Odontaspis	O. borodini				A sand shark, type locality of O. borodini and O. hynei.
	O. hynei
	O. speyeri
	O. substriatus
	?O. winkleri
Pachygaleus	P. lefevrei				A houndshark.
Physogaleus	P. americanus				A requiem shark. Type locality of P. americanus.
	P. tertius
Pristis	P. sp.		Late Paleocene		A sawfish.
Pseudodontaspis	P. lauderdalensis				A sand shark, type locality of species.
Rhinobatos	R. sp.				A guitarfish.
Striatolamia	S. macrota				A sand shark.

Ray-finned fishes

Based on the Paleobiology Database:^[6]

Ray-finned fishes of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Albula	A. eppsi	Lauderdale County, Mississippi	Early Eocene		A bonefish.
	A. oweni
Brychaetus	B. muelleri				A bonytongue.
Egertonia	E. isodonta				A phyllodontid.
Lepisosteus	L. sp.				A gar. Assigned to the European species L. suessionensis (itself a junior synonym of L. fimbriatus), but this is unlikely due to their differing ranges.[7]
Palaeocybium	P. proosti				A mackerel.
Phyllodus	P. toliapicus				A phyllodontid.
Pycnodus	P. bowerbanki				A pycnodont.
Trichiurides	T. sagittidens				A cutlassfish.

Reptiles

Based on the Paleobiology Database:^[4][5]

Reptiles of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Palaeophis	P. casei	Meridian, Mississippi	Early Eocene		A marine palaeophiid snake.
	P. littoralis
	P. virginianus
Tuscahomaophis	T. leggetti		Late Paleocene		An alethinophidian snake.

Mammals

The Tuscahoma Formation preserves a diversity of earliest Eocene-aged mammals. Almost all mammals are known only from isolated teeth. There appear to be significant differences in the faunal composition between the Tuscahoma Formation and the contemporaneous Bighorn Basin of the western US, indicating some level of provincialism in North American mammal species assemblages of the time. The formation appears to have been biased against the preservation of large-sized mammals, meaning that the majority of mammal remains from the formation are of smaller taxa.^[3]

Based on the Paleobiology Database and Dawson & Beard (2009):^[4][3]

Metatheria

Metatherians of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Mimoperadectes	M. sowasheensis	Meridian, Mississippi	Early Eocene		A peradectid.
Peratherium	P. mcgrewi				A herpetotheriid.

Cimolesta

Cimolestans of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Coryphodon	C. sp.	Meridian, Mississippi	Early Eocene		A pantodont.
Naranius	N. americanus				A cimolestid. Type locality of species.
Palaeosinopa	P. aestuarium				A pantolestid. Type locality of species.

Macroscelidea

Macroscelideans of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Haplomylus	H. meridionalis	Meridian, Mississippi	Early Eocene		An apheliscid.

Ungulates

Ungulates of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Diacodexis	D. sp.	Meridian, Mississippi	Early Eocene		An even-toed ungulate.
Ectocion	E. nanabeensis				A phenacodont. Type locality of species.
Hyracotherium	H. sp.				An odd-toed ungulate.

Pan-Carnivorans

Ungulates of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Eogale	E. parydros	Meridian, Mississippi	Early Eocene		A miacid carnivoramorph. Type locality of genus and species.
Gracilocyon	G. igniculus				A carnivoraform.
"Miacis"	"M." sp.				A carnivoramorph.
Prototomus	P. sp.				A sinopid hyaenodont.
Uintacyon	U. sp.				A carnivoraform.
Vassacyon	V. sp.				A carnivoraform.
Viverravus	V. laytoni				A viverravid carnivoramorph.
Viverriscus	V. omnivorus				A viverravid carnivoramorph. Type locality of genus and species.

Eulipotyphlans

Eulipotyphlans of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Colpocherus	C. mississippiensis				A sespedectid. Type locality of genus and species.
Diacocherus	D. dockeryi				An erinaceoid. Type localiy of species.
Plagioctenodon	P. dormaalensis				A nyctitheriid.
Talpavoides	T. dartoni				A stem-erinaceid.[8]
Wyonycteris	W. primitivus				A nyctitheriid. Type locality of species.

Apatotherians

Apatotherians of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Apatemys	A. pygmaeus	Meridian, Mississippi	Early Eocene		An apatemyid. Type locality of species.

Rodents

Rodents of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Corbarimys	C. nomadus	Meridian, Mississippi	Early Eocene		An ischyromyoid.[9]
Franimys	F. actites				An ischyromyid.
Paramys	P. dispar				An ischyromyid.
Tuscahomys	T. major				A cylindrodontid. Type locality of genus and species.
	T. medius
	T. minor

Primates

Primates of the Tuscahoma Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Choctawius	C. foxi		Meridian, Mississippi		An omomyid. Type locality of genus and species.
Teilhardina	T. magnoliana				An omomyid.

See also

• Earth sciences portal
• Mississippi portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Mississippi
• Paleontology in Mississippi