City of Mesa, AZ

Tonto National Forest Devonian Project



Fossil of primitive fish Asterolepis in foreground, with life reconstruction behind.

Fossil of primitive fish Asterolepis in foreground, with life reconstruction behind.


Museum Researchers: Principal Investigator Adjunct Curator Dr. Heidemarie Johnson
Location: Near Payson
Age: Middle to Upper Devonian, 380 million years before present
Geological Unit: Martin Limestone
Discoveries Include: The ancient fishes, Asterolepis, Bothriolepis, Arthrodira.
Comments: The beds containing the fish, Asterolepis apparently represent a mass death in a drying pond or ox bow lake, not far from the ancient ocean that covered much of Arizona.

Publications from Tonto National Forest Devonian Project
 
2001 In Search of Clues: Solving the Mystery of a 375 million year old Mass-Kill.
Heidemarie G. Johnson. Mesa Southwest Museum Bulletin 8:1.
2000 A New Antiarch (Class Placodermi) from Arizona.
Heidemarie G. Johnson (abstract). Mesa Southwest Museum Bulletin 7: 1.
1995 Devonian Fossil Fish from Central Arizona.
Heidemarie G. Johnson. Fossils of Arizona Symposium Proceedings Volume 3:1-6.