Talenkauen

Source: Wikipedia, the free encyclopedia.

Talenkauen
Temporal range:
Ma
Late Cretaceous
Holotype MPM-10001
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Ornithopoda
Clade: †Elasmaria
Genus: †Talenkauen
Novas et al. 2004
Species:
†T. santacrucensis
Binomial name
†Talenkauen santacrucensis
Novas et al. 2004

Talenkauen is a

Santa Cruz, Argentina.[1][2] It is based on MPM-10001A, a partial articulated skeleton missing the rear part of the skull, the tail, and the hands. The type and only species is Talenkauen santacrucensis.[2]

Discovery and naming

Lake Viedma, where the only known specimen of Talenkauen was found

One among a string of discoveries of ornithopods in South America, following taxa such as

Aonikenk language. The specific name santacrucensis refers to the province of Argentina where it was found.[2] Following its original, preliminary description, the taxon was described more thoroughly described in an unpublished PhD dissertation in 2007 by Andrea V. Cambiaso. In 2020 an extensive description was published by Sebastián Rozadilla and colleagues.[4]

It has been recognized that, nestled amongst the rock matrix of the holotype specimen, are a collection of minuscule bone fragments and teeth. Identifiable as the teeth of some degree of ornithopod, and associated with the adult specimen, this is considered to be a neonatal, or recently hatched, baby specimen of Talenkauen. It was described in a 2013 paper, which separated the specimen number MPM–10001 into MPM–10001A, for the adult specimen, and MPM–10001B, for the neonate. The specimen is one of only very few embryonic or hatchling ornithopod specimen, and was the very first discovered from the southern hemisphere. Wear on the tiny, 1.7mm wide tooth crowns indicate the individual had fed, meaning it was not an embryo and had hatched, but only recently before death. It was noted as possible that the adult had been practicing parental care due to the individuals being found together, but that more concrete evidence would be needed to confidently make such an assertion.[3]

Description

Life restoration

Talenkauen was rather like

derived iguanodonts lose this toe, retaining only the three middle toes. The humerus has reduced areas for muscle attachment, a featured shared with other South American ornithopods like Notohypsilophodon and Anabisetia. This and other similarities to South American ornithopods suggests that there may have been a distinct Southern Hemisphere ornithopod group, but at the time the authors cautioned that such an interpretation was not entirely justified. In 2015, the describers of Morrosaurus found that such a clade did indeed exist.[5]

Alternate view of the holotype, MPM-10001

Talenkauen is most noted for a set of smooth,

theropod dinosaurs. In birds, uncinate processes help to ventilate the lungs, working with rib cage muscles, and Novas and colleagues proposed a similar function for the plates of Talenkauen.[2] This homology was rejected in a more recent study by Richard Butler and Peter Galton because of the plates' form.[7] The plates were too thin and limited in location to have been very useful as defensive devices.[2]

Classification

Through

cladistic analysis, it was found to be more basal than Dryosaurus and Anabisetia, but more derived than Tenontosaurus and Gasparinisaura.[2] More recently, the describers of Macrogryphosaurus found their genus and Talenkauen to be related, and coined the clade Elasmaria for the two genera.[8] In 2015, several other Patagonian and Antarctic ornithopods were also found to be related.[5]

The simplified cladogram below results from analysis by Rozadilla et al., 2019, showing all members of Elasmaria forming a polytomy.[9]

Clypeodonta

Palaeoecology

Reconstructed skeleton

Talenkauen, as a basal ornithopod, would have been a small,

titanosaurid Puertasaurus[11] and the large predatory theropod Orkoraptor.[12]

References

Notes

  1. ^ Talenkauen was originally reported as being from the "Pari Aike Formation" and later reported as instead being from the Mata Amarilla Formation.[4] Geological studies found several names were being used for the same rock layers and advised use of the name Ceroo Fortaleza Formation over the former two as they were associated with incorrect dates or also used for other units.[1]

Citations

  1. ^
    doi:10.1111/bre.12272
    .
  2. ^ a b c d e f g h i Novas, Fernando E.; Cambiaso, Andrea V; Ambrioso, Alfredo (2004). "A new basal iguanodontian (Dinosauria, Ornithischia) from the Upper Cretaceous of Patagonia". Ameghiniana. 41 (1): 75–82.
  3. ^
    hdl:11336/8680
    .
  4. ^
    S2CID 155344014
    .
  5. ^
    doi:10.1016/j.cretres.2015.09.009
    .
  6. OCLC 985402380
    .
  7. ^
    doi:10.1016/j.cretres.2008.02.002
    .
  8. ^ a b Calvo, J.O.; Porfiri, J.D.; Novas, F.E. (2007). "Discovery of a new ornithopod dinosaur from the Portezuelo Formation (Upper Cretaceous), Neuquén, Patagonia, Argentina". Arquivos do Museu Nacional. 65 (4): 471–483.
  9. S2CID 155344014
    .
  10. ISBN 978-0-520-24209-8
    .
  11. doi:10.22179/REVMACN.7.344
    .
  12. doi:10.1016/j.cretres.2008.01.001
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Talenkauen&oldid=1213186714"