Pygostyledescribes a skeletal condition in which the final fewcaudalvertebraeare fused into a singleossification,supporting the tailfeathersand musculature. In modernbirds,therectricesattach to these. The pygostyle is the main component of theuropygium,a structure colloquially known as thebishop's nose,parson's nose,pope's nose,orsultan's nose.This is the fleshy protuberance visible at the posterior end of abird(most commonly achickenorturkey) that has been dressed forcooking.It has a swollen appearance because it also contains theuropygial glandthat producespreen oil.
Evolution
editPygostyles probably began toevolvevery early in theCretaceousperiod, perhaps 140 – 130 million years ago. The earliest knownspeciesto have evolved a pygostyle were members of theConfuciusornithidae.[citation needed]The structure provided an evolutionary advantage, as a completely mobile tail as found in species such asArchaeopteryxis detrimental to its use for flight control. Modern birds still develop longer caudal vertebrae in theirembryonicstate, which later fuse to form a pygostyle.
There are two main types of pygostyle:[citation needed]one, found in Confuciusornithidae,Enantiornithes,and some otherMesozoicbirds, as well as in someoviraptorosaurslikeNomingia,is long and rod- ordagger blade-like. None of the known fossils with such pygostyles show traces of well-developed rectrices. The tail feathers in these animals consisted ofdownyfuzz and sometimes 2–4 central "streamers" such as those found in some specimens ofConfuciusornisor inParaprotopteryx.[1]
By contrast, the function of the pygostyle in theterrestrialNomingiais not known. It is notable however that its older relativeCaudipteryxhad no pygostyle but a "fan" of symmetrical feathers which were probably used in social display. Perhaps such ornaments were widespread inCaenagnathoideaand their relatives, and ultimately the oviraptorosaurian pygostyle evolved to help support them. The relatedSimilicaudipteryx,described in 2008, also had a rod-like pygostyle, associated with a fan of tail feathers.[2]
The other pygostyle type isplowshare-shaped. It is found inOrnithurae(living birds and their closest relatives), and in almost all flying species is associated with an array of well-developed rectrices used in maneuvering. The central pair of these attach directly to the pygostyle, just as inConfuciusornis.The other rectrices of Ornithurae are held in place and moved by structures calledbulbi rectricium(rectricial bulbs), a complex feature of fat and muscles located on either side of the pygostyle. The oldest known species with such a pygostyle isHongshanornis longicresta.[3]
As evidenced by theoviraptorosauriancases, the pygostyleevolvedat least twice, and rod-shaped pygostyles seem to have evolved several times, in association with shortening of the tail but not necessarily with a retractable fan of tail feathers. In other words, the pygostyles of oviraptorosaurs andConfuciusorniswere likely weight-saving measures, and the specialized "true" pygostyles of ornithurans were adapted from these later to improve flight performance.[1]
The birdcladePygostyliawas named in 1996, byLuis Chiappe,for the presence of this feature and roughly corresponds to its appearance in the bird family tree, though the feature itself is not included in its definition.[4]In 2001,Jacques GauthierandKevin de Queiroz(2001) re-defined Pygostylia to refer specifically to theapomorphyof a short tail bearing an avian pygostyle.
Etymology
edit
"Pygostyle" is formed fromAncient Greekwords, literally meaning "rump pillar".
The insulting equation of the pygostyle with the noses of dignitaries dates back to 18th century Britain wherepope's nosefirst appears (in 1786). The formparson's noseappears much later, dated to 1839. The usage is somewhat dependent on either a Catholic or Protestant viewpoint.[5]
The formsbishop's noseandsultan's noseare 20th century variants.
As food
editTurkey tailorturkey butthas an international exportation market in places such asMicronesia,Samoa,andGhana.The turkey tail is commonly exported from America because it is considered unhealthy and cut off the normal turkey.[6]After World War II, cheap imported turkey tails became popular in Samoa. Because the cut has a very high fat content, it was banned from 2007 to 2013 to combat obesity, only allowed back when Samoa joined the World Trade Organization. The meat is otherwise used inpet food.[7]
Footnotes
edit- ^abClarkeet al.(2006)
- ^Xu, X.; Zheng, X.; You, H. (2010). "Exceptional dinosaur fossils show ontogenetic development of early feathers".Nature.464(7293): 1338–1341.Bibcode:2010Natur.464.1338X.doi:10.1038/nature08965.PMID20428169.S2CID205220207.
- ^O'Connor, J.K.; Gao, K.-Q.; Chiappe, L.M. (2010)."A new ornithuromorph (Aves: Ornithothoraces) bird from the Jehol Group indicative of higher-level diversity"(PDF).Journal of Vertebrate Paleontology.30(2): 311–321.doi:10.1080/02724631003617498.S2CID53489175.
- ^Chiappe, L. (1997). "The Chinese early birdConfuciusornisand the paraphyletic status of Sauriurae ".Journal of Vertebrate Paleontology.17(3): 37A.doi:10.1080/02724634.1997.10011028.
- ^"Green's Dictionary of Slang".Retrieved2019-06-28.
- ^Singer, Merrill (2014)."Following the turkey tails: neoliberal globalization and the political ecology of health"(PDF).Journal of Political Ecology.21:436–451.doi:10.2458/v21i1.21145.
- ^Robert Siegel (2013-05-09)."Samoans Await The Return Of The Tasty Turkey Tail".NPR.
References
edit- Clarke, Julia A.; Zhou, Zhonghe; Zhang, Fucheng (2006)."Insight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology ofYixianornis grabaui".Journal of Anatomy.208(3): 287–308.doi:10.1111/j.1469-7580.2006.00534.x.PMC2100246.PMID16533313.Electronic Appendix
- He, T.; Wang, X.-L.; Zhou, Z.-H. (2008). "A new genus and species of caudipterid dinosaur from the Lower Cretaceous Jiufotang Formation of western Liaoning, China".Vertebrata PalAsiatica.46(3): 178–189.