Dicraeosauridae

Dicraeosaurids
Temporal range: Middle Jurassic - Early Cretaceous,
166–122 Ma
Amargasaurus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: †Sauropodomorpha
Clade: †Sauropoda
Superfamily: †Diplodocoidea
Clade: †Flagellicaudata
Family: †Dicraeosauridae
Janensch, 1929
Genera

Dicraeosauridae is a family of diplodocoid sauropods who are the sister group to Diplodocidae. Dicraeosaurids are a part of the Flagellicaudata, along with Diplodocidae. Dicraeosauridae includes genera such as Amargasaurus, Suuwassea, Dicraeosaurus, and Brachytrachelopan. Specimens of this family have been found in North America, Asia, Africa, and South America.[1] In 2023, a dicraeosaurid fossil was discovered in India for the first time.[2] Their temporal range is from the Early or Middle Jurassic to the Early Cretaceous.[3][4][5] Few dicraeosaurids survived into the Cretaceous, the youngest of which was Amargasaurus.[6]

The group was first described by German paleontologist Werner Janensch in 1914 with the discovery of Dicraeosaurus in Tanzania.[7] Dicraeosauridae are distinct from other sauropods because of their relatively short neck size and small body size.[3]

The clade is monophyletic and well-supported phylogenetically with thirteen unambiguous synapomorphies uniting it.[6] They diverged from Diplodocidae in the Mid-Jurassic, as evidenced by the diversity of dicraeosaurids in both South America and East Africa when Gondwana was still united by land.[6] However, there is some disagreement among paleontologists on the phylogenetic placement of Suuwassea, the only genus of the Dicraeosauridae to be found in North America. It has been characterized as a basal dicraeosaurid by some and a member of the Diplodocidae by others.[6][8] The placement of Suuwassea within Dicraeosauridae or Diplodocidae has substantial biogeographic implications for the evolution of Dicraeosauridae.[9]

  1. ^ Gallina, Pablo A.; Apesteguía, Sebastián; Haluza, Alejandro; Canale, Juan I. (2014-05-14). "A Diplodocid Sauropod Survivor from the Early Cretaceous of South America". PLOS ONE. 9 (5): e97128. Bibcode:2014PLoSO...997128G. doi:10.1371/journal.pone.0097128. ISSN 1932-6203. PMC 4020797. PMID 24828328.
  2. ^ "The Oldest Plant-Eating Dinosaur Has Been Found in India". New York Times. 19 August 2023. Retrieved 23 August 2023.
  3. ^ a b Rauhut, Oliver W. M.; Remes, Kristian; Fechner, Regina; Cladera, Gerardo; Puerta, Pablo (2005-06-02). "Discovery of a short-necked sauropod dinosaur from the Late Jurassic period of Patagonia". Nature. 435 (7042): 670–672. Bibcode:2005Natur.435..670R. doi:10.1038/nature03623. ISSN 1476-4687. PMID 15931221. S2CID 4385136.
  4. ^ Carabajal, Ariana Paulina; Carballido, José L.; Currie, Philip J. (2014-06-07). "Braincase, neuroanatomy, and neck posture of Amargasaurus cazaui (Sauropoda, Dicraeosauridae) and its implications for understanding head posture in sauropods". Journal of Vertebrate Paleontology. 34 (4): 870–882. doi:10.1080/02724634.2014.838174. hdl:11336/19365. ISSN 0272-4634. S2CID 85748606.
  5. ^ Xing Xu; Paul Upchurch; Philip D. Mannion; Paul M. Barrett; Omar R. Regalado-Fernandez; Jinyou Mo; Jinfu Ma; Hongan Liu (2018). "A new Middle Jurassic diplodocoid suggests an earlier dispersal and diversification of sauropod dinosaurs". Nature Communications. 9 (1): Article number 2700. Bibcode:2018NatCo...9.2700X. doi:10.1038/s41467-018-05128-1. PMC 6057878. PMID 30042444.
  6. ^ a b c d Whitlock, John A. (2011-04-01). "A phylogenetic analysis of Diplodocoidea (Saurischia: Sauropoda)". Zoological Journal of the Linnean Society. 161 (4): 872–915. doi:10.1111/j.1096-3642.2010.00665.x. ISSN 1096-3642.
  7. ^ Weishampel, DB; Dodson, P; Osmolska, H (2007). The Dinosauria. University of California Press. ISBN 978-0520254084.
  8. ^ Woodruff, D. Cary; Fowler, Denver W. (2012-07-01). "Ontogenetic influence on neural spine bifurcation in Diplodocoidea (Dinosauria: Sauropoda): a critical phylogenetic character". Journal of Morphology. 273 (7): 754–764. doi:10.1002/jmor.20021. ISSN 1097-4687. PMID 22460982. S2CID 206091560.
  9. ^ Harris, Jerald D. (2006-01-01). "The significance of Suuwassea emilieae (Dinosauria: Sauropoda) for flagellicaudatan intrarelationships and evolution". Journal of Systematic Palaeontology. 4 (2): 185–198. doi:10.1017/S1477201906001805. ISSN 1477-2019. S2CID 9646734.