Reeve's Bonebed

A geological formation in Presidio county, Texas, with the coordinates of 29.9° N, 104.2° W. It is placed in the late Eocene and early Oligocene.

Geology

Reeves bonebed lies in the Vieja Formation

Ecology

The University of Texas holds a large collection of fossils from Reeves bonebed. The number of specimins held in their collection from the Reeve's Bonebed are displayed in the abundance column^[1]:

Mammals

Order	Family	Genus	Abundance	Notes
Cetartiodactyla	Merycoidodontidae	Merycoidodon	91
	Merycoidodontidae	Bathygenys	709	hundreds of endocasts (see below)
	Leptomerycidae	Hendryomeryx defordi	2
	Leptomerycidae	Leptomeryx	10
	Oromerycidae	Eotylopus reedi	1
	Agriochoeridae	Agriochoerus	15
	Protoceratidae	Leptotragulus	1
	Protoceratidae	Heteromeryx defordi	2
Rodentia	Eutypomyidae	Eutypomys inexpectatus	13
	Ischyromyidae	Pseudotomus johanniculi	1	holotype
	Ischyromyidae	Leptotomus	1
	Cylindrodontidae	Ardynomys	1
	Cylindrodontidae	Cylindrodon fontis	3
Perissodactyla	Tapiridae	Colodon	4
	Equidae	Mesohippus	11
	Hyracodontidae	Hyracodon primus	1
	Brontotheriidae	Menodus bakeri	1
Carnivora	Miacoidea	Miacis cognitus	1	holotype
Creodonta	Hyaenodontidae	Hyaenodon	2

For fossils of which an exact genus cannot be assigned, there have been discovered...

gastropods

testudinids

Pholidosteids

Oreodont Braincasts

Reeves bonebed is known for the recovery of casts of the brain cavity of oreodonts called endocasts^[2]. When and animal dies and the soft tissues decay, sediments fill the orafices left, including the brain case. If the bone falls apart, the fossil that used to be housed on the inside of the skull can remain. Hunreds of brain casts, mainly from Bathygenys, were recovered from Reeves bonebed and have been used to guage the size of the brain as well as the size of the lobes. Physical arrangement of the brain can lead to clues about the life of the living animal, such as how important smell was to it, as used in CT scans of Tyrannosaurus. Studies involving more than 150 of these endocasts have been preformed from the Reeves bonebed samples.^[3]

References

^ University of Texas, Austin. Bonebed&county=&state=&specid=&geol_form=&epoch=&site_no=&showimage=&geog=&country=&others=&geol=&epoch=&period=&age=&era=&strat=&formation=&group=&horizon=&member=&sorted_by= "Reeves bonebed". {{cite web}}: Check |url= value (help)
^ "Oreodont braincasts".
^ Macrini, Thomas E. "Description of a Digital Cranial Endocast of Bathygenys reevesi (Merycoidodontidae; Oreodontoidea) and Implications for Apomorphy-Based Diagnosis of Isolated, Natural Endocasts".

[1] University of Texas, Austin. Bonebed&county=&state=&specid=&geol_form=&epoch=&site_no=&showimage=&geog=&country=&others=&geol=&epoch=&period=&age=&era=&strat=&formation=&group=&horizon=&member=&sorted_by= "Reeves bonebed". {{cite web}}: Check |url= value (help)

[2] "Oreodont braincasts".

[3] Macrini, Thomas E. "Description of a Digital Cranial Endocast of Bathygenys reevesi (Merycoidodontidae; Oreodontoidea) and Implications for Apomorphy-Based Diagnosis of Isolated, Natural Endocasts".

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