Enantiornis
Temporal range: Maastrichtian
~70 Ma
↓
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Avialae
Clade: †Enantiornithes
Order: †Enantiornithiformes
Martin, 1983
Family: †Enantiornithidae
Nesov, 1984
Genus: †Enantiornis
Walker, 1981
Species:
†E. leali
Binomial name
†Enantiornis leali
Walker, 1981

Enantiornis is a genus of Enantiornithes. The type and only currently accepted species E. leali is from the Late Cretaceous Lecho Formation at El Brete, Argentina. It was described from specimen PVL-4035, a coracoid, proximal scapula and proximal humerus found close to each other and suspected to represent the left shoulder of a single individual.[1]

Description

The genus and the larger group it belongs to, get their name from the reversed scapula-coracoid connection they possess compared to modern birds and the hesperornithids that were their contemporaries: Enanti "opposite", ornis is "bird".[1]

Another left shoulder and wing, almost complete and found associated in one lump of rock, as well as a few isolated bones were also assigned to this species mainly based on size. It is among the largest enantiornithines discovered to date,[2] with a length in life of around 78.5 cm (30.9 in), hip height of 34 cm (13 in), weight of 6.75 kg (14.9 lb),[3] and wingspan comparable to herring gulls, around 1.2 m (3 ft 11 in).[2] Its ecological niche resembled that of a mid-sized vulture or eagle.

Taxonomy and phylogeny

E. leali was possibly fairly closely related to Avisaurus, another genus of probably carnivorous enantiornithines, though its exact relationship is unclear. It was placed in a family of its own, Enantiornithidae. Other species from Asia that were previously placed in this genus are now split off. The former Enantiornis martini is now placed in Incolornis, while the former Enantiornis walkeri is now tentatively assigned to Explorornis. The reason for this is that these species were described when the diversity of enantiornithines was underestimated.

As no hindlimb elements are known from Enantiornis, it might include one of the El Brete enantiornithines known only from leg bones, namely Lectavis, Soroavisaurus or Yungavolucris. However, these apparently were all smaller than Enantiornis. Hindlimb material tentatively assigned to Martinavis and Elbretornis seems somewhat and a lot too small, respectively, to represent Enantiornis.[4]

The cladogram below is from Wang et al., 2022:[5]

Enantiornithes
l

Key to letters:

b = Boluochia
c = Cathayornis
e = Enantiophoenix
f = Houornis
h = Longipteryx
i = Parabohaiornis
j = Pterygornis
l = Vorona
m = Yuanjiawaornis
n = Yungavolucris

References

  1. ^ a b Walker, C. A. (1981). "New subclass of birds from the Cretaceous of South America". Nature. 292 (5818): 51–53. Bibcode:1981Natur.292...51W. doi:10.1038/292051a0. S2CID 4340858.
  2. ^ a b Colin Tudge (October 20, 2009). The Bird: A Natural History of Who Birds Are, Where They Came From, and How They Live. Crown. p. 64. ISBN 9780307459763. Retrieved 29 August 2022.
  3. ^ Rubén Molina-Pérez, Asier Larramendi, David Connolly, Gonzalo Ángel Ramírez Cruz, Andrey Atuchin (June 25, 2019). Dinosaur Facts and Figures: The Theropods and Other. Princeton University Press. p. 281. ISBN 9780691190594. Retrieved 29 August 2022.((cite book)): CS1 maint: multiple names: authors list (link)
  4. ^ Cyril A. Walker & Gareth J. Dyke (2009). "Euenantiornithine birds from the Late Cretaceous of El Brete (Argentina)" (PDF). Irish Journal of Earth Sciences. 27: 15–62. doi:10.3318/IJES.2010.27.15. S2CID 129573066. Archived from the original (PDF) on 2012-03-20.
  5. ^ Wang, Xuri; Cau, Andrea; Luo, Xiaoling; Kundrát, Martin; Wu, Wensheng; Ju, Shubin; Guo, Zhen; Liu, Yichuan; Ji, Qiang (2022-02-11). "A new bohaiornithid-like bird from the Lower Cretaceous of China fills a gap in enantiornithine disparity". Journal of Paleontology. 96 (4): 961–976. doi:10.1017/jpa.2022.12. ISSN 0022-3360. S2CID 247432530.


Categories