Morrison
1,191 occ.
157 taxa (37 genera)
1 countries
Description
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
Genera
37 genera
Temporal range
252
201
145
66
0 Ma
Geological group / Member
Brushy Basin
395
Lake Como
110
Salt Wash
68
Talking Rocks
44
Kenton
39
Indian Fort
31
Unit B
12
Tidwell
8
Boise
3
Cimarron
3
Top countries
🇺🇸 United States
1191
Depositional environments
Terrestrial indet.
287
Channel
184
Wet floodplain
173
Crevasse splay
133
Pond
93
Coarse channel fill
85
Fine channel fill
41
Lacustrine indet.
39
dry floodplain
32
Fluvial indet.
28
Top collectors
W. Reed
67
C. Gilmore
51
J. Jensen
47
J. B. Hatcher
38
Stokes
38
J. W. Stovall
35
V. Jones
33
O. Mateus
33
E. Jones
31
P. Kaisen
30
Utterback
28
R. Peterson
26
Collection activity by decade
1850s
1
1860s
1
1870s
120
1880s
55
1890s
51
1900s
162
1910s
6
1920s
62
1930s
131
1940s
38
1950s
19
1960s
51
1970s
128
1980s
140
1990s
294
2000s
191
2010s
112
2020s
3