The Geology of Delaware

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Land Mammals: Phylum Chordata

Land Mammals:  Phylum Chordata<br>Source:

Land mammal fossils were discovered in 1992 in the lower part of the Calvert formation at the Pollack Farm site. During the short time the pit was open, the collection grew to become the most diverse tertiary land mammal fauna known north of Florida on the eastern half of North America.

The gathering, collected from the lower Miocene formation, includes at least 26 species representing at least 17 families in 7 orders (listed below).


  • Soricomorpha (Shrews, moles)
  • Erinaceomorpha (Hedge hogs)
  • Chiroptera (Bats)
  • Rodentia (Rats, mice)
  • Carnivora (Bears, wolves)
  • Perissodactyla (Rhinoceros, horses)
  • Artiodactyla (Deer)

The Collection of Miocene land mammal fossils, especially north of Florida, is relatively minimal. Only four localities distancing between Georgia and New Jersey yielded significant Miocene fossil beds. Although single teeth and parts of postcranial elements represent the majority of land mammals of the Pollack Farm local fauna, the sites diversity of species elevates the importance of the Pollack Farms location.

Click the image or the link below to view the Land Mammal collection!


Photographs from DGS Special Publication No. 21, 1998, R.N. Benson, ed.
Top left image: http:/

Photo Gallery
A-C. Plesiosores cf. P. coloradensis, A-C are all Insectivores<br>
D-E. Insectivores<br>F-G. Bats, Microchiroptera<br>
K-L. Rodents, "Monosaulax" sp.<br>
H-J, Rodents<br>H. Anchitheriomys, fragment of incisor enamel<br>J. "Monosaulax" sp<br>
M-N. Proheteromys magnus, Rodents<br>
J. Cynelos sp., mandibular fragment with parts<br>
D-E. Part of right mandible of bassariscine<br>
I. Cynelos sp., mandibular fragment with parts<br>
H. Amphicyon intermedius<br>
O-P. Tomarctus cf. T. canavus<br>
A-B. ?Hemicyon sp., Ursidae<br>
M-Q. Parahippus leonensis<br>
L. Parahippus leonensis<br>
F-G Archaeohippus sp.<br>
U-V. Parahippus leonensis<br>
C-D. Tylocephalonyx sp., Chalicothere<br>
E. Tylocephalonyx sp., Chalicothere, the left third metatarsal<br>Miocene Land Mammal illustrations from Figure 4, DGS Special Publication No. 20, by Emry, R.J., and Eshelman, R.E., 1998.
I,M,N. Rhinocerotidae., rhinoceros<br>
O. Rhinocerotidae., rhinoceros <br>
M. ????????<br>
K-L.,Desmathyus or Hesperhys <br>Miocene Land Mammal illustrations from Figure 5, DGS Special Publication No. 20, by Emry, R.J., and Eshelman, R.E., 1998.
I-J. Cynorca sociale. right second and third metatarsal<br>
P-T. Ruminantia, genus uncertain<br>
D,E,H. Cynorca sociale<br>