Fruitland Formation

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Fruitland formation
Stratigraphic range: Campanian,[1] 75.5–74.5Ma
Type Geological formation
Sub-units Fossil Forrest Member,
Ne-nah-ne-zad Member
Underlies Kirtland Formation
Overlies Pictured Cliffs Sandstone
Location
Region  New Mexico  Colorado
Country  USA

The Fruitland Formation is a sedimentary geological formation containing layers of sandstone, shale, and coal. It was laid down in marshy delta conditions, with poor drainage and frequent flooding, under a warm, humid and seasonal climate. It is found in the San Juan Basin in the states of New Mexico and Colorado, in the United States of America. The Fruitland Formation contains beds of bituminous coal that are mined in places along the outcrop. Since the 1980s, the coal beds of the Fruitland Formation have yielded large quantities of coalbed methane. The productive area for coalbed methane straddles the Colorado-New Mexico state line, and is one of the most productive areas for coalbed methane in the United States.

The Fruitland is underlain by the Pictured Cliffs Sandstone, and overlain by the more recent Kirtland Formation. The sequence of rocks represents the final filling of the Cretaceous seaway. The underlying Pictured Cliffs is a marginal marine sandstone, deposited in an environment similar to offshore barrier islands of the southeast United States. As the seaway retreated, the Pictured Cliffs was covered by the Fruitland Formation, which was deposited in near-shore swampy lowlands. The formation is dated to the late Campanian (part of the Cretaceous period), and was deposited over a period of about a million years. Radiometric dating from just below the base of the formation has yielded an age of 75.56 ± 0.41 Ma ago. An ash bed lying below the upper boundary with the Kirtland Formation has been dated to 74.55 ± 0.29 Ma ago.[1]

The formation is subdivided into the upper Fossil Forrest Member (deposited between about 75-74.5 million years ago) and the lower Ne-nah-ne-zad Member (deposited from 75.5-75 million years ago).[1] The Fossil Forrest member is considered to be part of the Hunter Wash, fauna shared with the overlying lower Kirtland Formation.[1]

Paleofauna[edit]

Ornithischians[edit]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Ornithischians of the Fruitland Formation
Genus Species Location Member Abundance Notes Images

Chasmosaurus[2]

Indeterminate[2]

Corythosaurus[3]

Indeterminate[3]

Kritosaurus[4]

K. navajovius[4]

Fruitland remains once attributed to Kritosaurus navajovius are now regarded as indeterminate hadrosaurine remains.[5]

Monoclonius[6]

Indeterminate[6]

Remains previously referred to a possible Monoclonius are now regarded as indeterminate ceratopsid remains.[5]

Hadrosauridae indet.[7]

Intermediate[7]

  • Fossil Forest[7]

One print.[7]

Giant hadrosaur track, indicating an individual larger than Shantungosaurus, the largest known hadrosaur known.[7]

Parasaurolophus[5]

P. cyrtocristatus[5]

  • Fossil Forest[8]

One specimen, holotype

Pentaceratops[5]

P. fenestratus[5]

A jr. synonym of P. sternbergii.[5]

P. stenbergii[5]

  • Fossil Forest[9]

Specimens including holotype

Also found in the Kirtland Formation.

Stegoceras[10]

S. novomexicanum[10]

"(holotype) NMMNH P-33898, nearly complete frontoparietal" and "SMP VP-2555, greater posterior part of left frontal and anterior-most portions of left and right frontals"[10]

Also found in the lower Kirtland Formation.

S. validum[1]

Single tooth

A partial skull once referred to Stegoceras validum is now regarded as a distinct species, S. novomexicanum.[1]

Thescelosaurus[11]

Indeterminate[11]

Single tooth

A tooth once referred to Thescelosaurus is now regarded as belonging to an indeterminate ornithopod.[1]

Saurischians[edit]

Some remains (OMNH 10131) of Bistahieversor, a tyrannosauroid from the overlying Kirtland Formation, may actually have originated in the upper Fruitland Formation.[12]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Saurischians of the Fruitland Formation
Genus Species Location Member Abundance Notes Images

Tyrannosauridae

Indeterminate[1][13][14]

Teeth

Ornithomimus[15]

Indeterminate[15]

?Troodontidae[5]

Indeterminate

Formerly identified as Paronychodon sp., referral to Troodontidae doubtful.[16]

Saurornitholestes[1]

S. langstoni?[1]

Teeth[1]

Struthiomimus[1]

Indeterminate[1]

See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k l m Sullivan, R.M., and Lucas, S.G. 2006. "The Kirtlandian land-vertebrate "age" – faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America." New Mexico Museum of Natural History and Science, Bulletin 35:7-29.
  2. ^ a b Listed as "?Chasmosaurus sp." in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  3. ^ a b Listed as "?Corythosaurus sp." in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  4. ^ a b Listed as "?Kritosaurus navajovius" in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  5. ^ a b c d e f g h i "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  6. ^ a b Listed as "?Monoclonius sp." in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  7. ^ a b c d e Hunt & Lucas (2003): A New Hadrosaur Track from the Upper Cretaceous Fruitland Formation of Northwestern New Mexico. 379 New Mexico Geological Society Guidebook, 54th Field Conference, Geology of the Zuni Plateau, 2003, p. 379-381.
  8. ^ Hunt, A. P., & Lucas, S. G. (2003). Origin and stratigraphy of historic dinosaur quarries in the Upper Cretaceous Fruitland Formation of the Fossil Forest research Natural Area, northwestern New Mexico. New Mexico Geological Society Guidebook, 54, 383-388.
  9. ^ "Kirtlandian Index Fossils," in Sullivan and Lucas (2006). Page 10.
  10. ^ a b c d Steven E. Jasinski and Robert M. Sullivan (2011). "Re-evaluation of pachycephalosaurids from the Fruitland-Kirtland transition (Kirtlandian, late Campanian), San Juan Basin, New Mexico, with a description of a new species of Stegoceras and a reassessment of Texascephale langstoni". Fossil Record 3. New Mexico Museum of Natural History and Science, Bulletin 53: 202–215. 
  11. ^ a b Listed as "?Thescelosaurus sp." in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  12. ^ Carr, T.D. and Williamson, T.E. (2010). "Bistahieversor sealeyi, gen. et sp. nov., a new tyrannosauroid from New Mexico and the origin of deep snouts in Tyrannosauroidea." Journal of Vertebrate Paleontology, 30(1): 1-16. doi:10.1080/02724630903413032
  13. ^ Listed as "?Albertosaurus sp." in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  14. ^ Listed as "?Gorgosaurus libratus" in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  15. ^ a b Listed as "?Ornithomimus sp." in "3.3 New Mexico, United States; 7. Fruitland Formation," in Weishampel, et al. (2004). Page 580.
  16. ^ David C. Evans, Derek William Larson, Thomas Michael Cullen & Robert M Sullivan (2014) ‘Saurornitholestes’ robustus is a troodontid (Dinosauria: Theropoda). Canadian Journal of Earth Sciences (advance online publication) doi: 10.1139/cjes-2014-0073 http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2014-0073#.U4yjc_ldXTo
  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.