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 specimens held in their collection from the Reeve's Bonebed are displayed in the abundance column^[1]:

Mammals

Order	Family	Genus	Abundance (?/870)	Notes
Cetartiodactyla	Merycoidodontidae	Merycoidodon	91: midly common
	Merycoidodontidae	Bathygenys	709: extremly common	hundreds of endocasts (see below)
	Leptomerycidae	Hendryomeryx defordi	2: exteremly rare
	Leptomerycidae	Leptomeryx	10: rare
	Oromerycidae	Eotylopus reedi	1: extremly rare
	Agriochoeridae	Agriochoerus	15: average abundance
	Protoceratidae	Leptotragulus	1: exteremly rare
	Protoceratidae	Heteromeryx defordi	2: exteremly rare
Rodentia	Eutypomyidae	Eutypomys inexpectatus	13: average abundance
	Ischyromyidae	Pseudotomus johanniculi	1: exteremly rare	holotype
	Ischyromyidae	Leptotomus	1: exteremly rare
	Cylindrodontidae	Ardynomys	1: exteremly rare
	Cylindrodontidae	Cylindrodon fontis	3: exteremly rare
Perissodactyla	Tapiridae	Colodon	4: rare
	Equidae	Mesohippus	11: average abundance
	Hyracodontidae	Hyracodon primus	1: exteremly rare
	Brontotheriidae	Menodus bakeri	1: exteremly rare
Carnivora	Miacoidea	Miacis cognitus	1: exteremly rare	holotype
Creodonta	Hyaenodontidae	Hyaenodon	2: exteremly rare

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 orifices 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. Hundreds of brain casts, mainly from Bathygenys, were recovered from Reeves bonebed and have been used to gauge 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 performed 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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