Youngina

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Youngina
Temporal range:
Ma
Juveniles
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Diapsida
Clade: Neodiapsida
Family: †Younginidae
Genus: †Youngina
Broom 1914
Type species
†Youngina capensis

Youngina (named after

Karoo Red Beds of South Africa.[1] This, and a few related forms, make up the family Younginidae, within the order Eosuchia (proposed by Broom in 1914). Eosuchia, having become a wastebasket taxon for many probably distantly-related primitive diapsid reptiles ranging from the Late Carboniferous to the Eocene, Romer proposed that it be replaced by Younginiformes (that included Younginidae and the Tangasauridae, ranging from the Permian to the Triassic
).

Taxonomy

Skull diagram

Youngina is known from several specimens. Many of these were attributed to as separate genera and species (such as Youngoides and Youngopsis), but it was later realized that they were not distinct from Y. capensis.[2][3] The holotype specimen of Youngina, discovered by Broom himself,[2] was described briefly in 1914.[4] The "Youngoides romeri" specimen was first attributed to Youngina,[5] but later given its eponymous and separate designation in a later paper.[6] Acanthotoposaurus[7] is also a junior synonym of Youngina.[8]

Description

Scale diagram

Youngina could have been a moderately sized early reptile (

orthogenetic evolution of these characters. Though the palatobasal articulation is open,[9] it was probably immobile, similar to the skull of the tuatara,[10] contrary to some earlier claims made about the metakinetic mobility of basicranial joints in Youngina and other early diapsid reptiles.[11]

Phylogeny

Youngina was once thought to be closely related to

phylogenetic position of Youngina among early diapsids:[13]

References
  1. ^ Smith, R.; Evans, S. (1996). "New Material of Youngina: Evidence of Juvenile Aggregation in Permian Diapsid Reptiles" (PDF). Palaeontology. 39 (2): 289–303. Archived (PDF) from the original on 2019-07-30.
  2. ^
    hdl:10539/16290
    .
  3. ^ Evans, S. E. (1987). "The braincase of Youngina capensis (Reptilia: Diapsida; Permian)". Neues Jahrb. Geol. Paläontol. Monats. 1987: 193–203.
  4. doi:10.1111/j.1469-7998.1914.tb07729.x
    .
  5. S2CID 140142731
    .
  6. JSTOR 1298390
    .
  7. ^ Evans, S. E.; Van der Heever, J. A. (1987). "A new reptile (Reptilia: Diapsida) from the Upper Permian Daptocephalus zone of South Africa". South African Journal of Science. 83 (11): 724–730.
  8. ^ Reisz, R. R.; Modesto, S. P.; Scott, D. (2000). "Acanthotoposaurus bremneri and the origin of the Triassic archosauromorphreptile fauna of South Africa". South African Journal of Science. 96 (8): 443–445.
  9. ^ a b Gardner, Nicholas M.; Holliday, Casey M.; O'Keefe, F. Robin (2010). "The Braincase of Youngina capensis (Reptilia, Diapsida): New Insights from High-Resolution CT Scanning of the Holotype". Palaeontologia Electronica. 13 (3): 19A.
  10. S2CID 32965233
    .
  11. doi:10.1111/j.1096-3642.1980.tb00852.x
    .
  12. doi:10.1139/E09-038
    .
  13. PMID 21525061
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Youngina&oldid=1218559651"