Mother's Day Quarry (Jurassic of the United States)

Also known as Mothers Day Site, MDQ, MT-1

Where: Carbon County, Montana (45.2° N, 108.8° W: paleocoordinates 40.5° N, 52.8° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Morrison Formation, Kimmeridgian (157.3 - 152.1 Ma)

• "lower half of the Upper Jurassic Morrison Formation, approximately 12 m above the underlying Swift Formation"

• bed-level stratigraphic resolution

Environment/lithology: crevasse splay; massive, fine-grained, pebbly, intraclastic, gray, yellow, argillaceous, calcareous sandstone

• "a levee or overbank deposit"
• "a muddy fine-grained sandstone"; "The bone bed matrix consists of light brown very fine-grained sand and silt-to-clay sized particles. The matrix is composed primarily of quartz grains bound by calcareous cement but also includes trace amounts of feldspar...clay rip-up clasts and sparsely distributed pebbles and carbonate nodules occur as minor components of the bone bed...the MDQ deposit lacks definitive indicators of paleopedogenesis"; "a largely homogenous, massive, muddy, grayish-yellow siltstone approximately 4 m thick"

Size classes: macrofossils, mesofossils

Preservation: soft parts

Collected by MOR, CMC in 1994-2003

Collection methods: quarrying, mechanical,

• discovered by MOR crews, then worked by Cinicinnati Museum Center

Primary reference: C. E. Turner and F. Peterson. 1999. Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, U.S.A. In D. D. Gillette (ed.), Vertebrate Paleontology in Utah, Utah Geological Survey Miscellaneous Publication 99-1:77-114 [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 69890: authorized by Matthew Carrano, entered by Matthew Carrano on 08.03.2007, edited by Jonathan Tennant

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
"Gymnospermae indet." = Pinophyta3
"Gymnospermae indet." = Pinophyta3 Reveal 1996
leaf and other fragments
Branchiopoda
 Diplostraca - Lioestheriidae
cf. Lioestheria sp.3 Deperet and Mazeran 1912 clam shrimp
Reptilia
 Ornithischia - Stegosauridae
Stegosaurus sp.1 Marsh 1877 ornithischian
 Theropoda -
Theropoda indet.2 Marsh 1881 theropod
teeth
 Theropoda - Dromaeosauridae
Dromaeosauridae indet. Colbert and Russell 1969 maniraptoran
tooth
 Saurischia - Diplodocidae
Diplodocus sp.3 Marsh 1878 diplodocine
"Diplodocus or Barosaurus (not Apatosaurus)"