Post by creature386 on Sept 21, 2013 19:21:12 GMT 5
Jinfengopteryx elegans
©Scott Hartman
Temporal range: Early Creataceous[1] (disputed)
Location: Jehol Biota, northern Hebei, northeastern China[2]
Scientific classification:
Theropoda
Deinonychosauria
Troodontidae
Jinfengopterynae
Jinfengopteryx
J. elegans[3]
Description:
Jinfengopteryx elegans was a small troodontid with a long tail,[1] long tail feathers (similar to those of Archaeopteryx) attached to it's 23 caudal vertebrae and a tall, short preorbital region in the skull.[2] J. elegans also has a proportionally robust snout.[4] The skull as whole is relatively triangular.[5] It's teeth are quite closely packed[2] and lack serrations. Instead, it has conical tooth crowns.[5] The diet of Jinfengopteryx is unsure, despite being a troodontid, it could have been a herbivore.[6]
The forelimbs were relatively short.[4]
So far, we only know the holotype specimen CAGS-IG-04-0801.[7]
Phylogenetic position:
Phylogeny of Troodontidae.[3]
The phylogenetic position of Jinfengopteryx is quite debatable. It was earlier regarded as a bird, related to Archaeopteryx, but more primitive, due to the shorter forelimb (compared to the hindlimb) and more closely packed teeth.[2] Jinfengopteryx later got separated from Archaeopteryx, because of it's more triangular skull, shorter forelimb and more robust snout.[4] In 2012, it got it's own subfamily called Jinfengopterynae. The subfamily is diagnosed by the big antorbital fenestra.[8] There are other unique features, like the bifurcated jugal. The specimen IGM 100/1126 (it has no Genus yet) is the closest relative of Jinfengopteryx within the group.[9]
Literature:
Ji Qiang (2008) Chinese Feathered Dinosaurs and the Origin of Birds ?A brief historical review In: Institute of Geology, Chinese Academy of Geological Sciences PDF (it starts at page 37)
JI Shu'an, JI Qiang (2007) Jinfengopteryx Compared to Archaeopteryx, with Comments on the Mosaic Evolution of Long-tailed Avialan Birds In: Acta Geologica Sinica Vol. 81(3), p. 337–343 online
Turner, Makovicky and Norell (2012) A review of dromaeosaurid systematics and paravian phylogeny. In: Bulletin of the American Museum of Natural History. 371, p. 1–206. PDF download link
Lü, J.?C., Xu, L., Liu, Y.?Q., Zhang, X.?L., Jia, S.H., and Ji, Q. (2010) A new troodontid theropod from the Late Cretaceous of central China, and the radiation of Asian troodontids. In: Acta Palaeontologica Polonica 55 (3): 381–388. PDF
Darren Naish (2011) Glorified dinosaurs: the origin and early evolution of birds In: Historical Biology: An International Journal of Paleobiology 23(4), p. 435-438, doi:10.1080/08912963.2010.530761
Lindsay E. Zanno, David D. Gillette, L. Barry Albright and Alan L. Titus (2009) A new North American therizinosaurid and the role of herbivory in ‘predatory’ dinosaur evolution Proc. R. Soc. B 276, p. 3505–3511 doi:10.1098/rspb.2009.1029
Footnotes:
[1] Ji Qiang (2008) p. 38 (according to the listing in the PDF, not in the original article)
[2] JI Shu'an, JI Qiang (2007) p. 337
[3] Turner, Makovicky and Norell (2012) p. 105
[4] Darren Naish (2011) p. 437
[5] Junchang Lü et al. (2010) p. 386
[6] Lindsay E. Zanno p. 3508
[7] JI Shu'an, JI Qiang (2007) p. 338
[8] Turner, Makovicky and Norell (2012) p. 106
[9] Turner, Makovicky and Norell (2012) p. 107
©Scott Hartman
Temporal range: Early Creataceous[1] (disputed)
Location: Jehol Biota, northern Hebei, northeastern China[2]
Scientific classification:
Theropoda
Deinonychosauria
Troodontidae
Jinfengopterynae
Jinfengopteryx
J. elegans[3]
Description:
Jinfengopteryx elegans was a small troodontid with a long tail,[1] long tail feathers (similar to those of Archaeopteryx) attached to it's 23 caudal vertebrae and a tall, short preorbital region in the skull.[2] J. elegans also has a proportionally robust snout.[4] The skull as whole is relatively triangular.[5] It's teeth are quite closely packed[2] and lack serrations. Instead, it has conical tooth crowns.[5] The diet of Jinfengopteryx is unsure, despite being a troodontid, it could have been a herbivore.[6]
The forelimbs were relatively short.[4]
So far, we only know the holotype specimen CAGS-IG-04-0801.[7]
Phylogenetic position:
Phylogeny of Troodontidae.[3]
The phylogenetic position of Jinfengopteryx is quite debatable. It was earlier regarded as a bird, related to Archaeopteryx, but more primitive, due to the shorter forelimb (compared to the hindlimb) and more closely packed teeth.[2] Jinfengopteryx later got separated from Archaeopteryx, because of it's more triangular skull, shorter forelimb and more robust snout.[4] In 2012, it got it's own subfamily called Jinfengopterynae. The subfamily is diagnosed by the big antorbital fenestra.[8] There are other unique features, like the bifurcated jugal. The specimen IGM 100/1126 (it has no Genus yet) is the closest relative of Jinfengopteryx within the group.[9]
Literature:
Ji Qiang (2008) Chinese Feathered Dinosaurs and the Origin of Birds ?A brief historical review In: Institute of Geology, Chinese Academy of Geological Sciences PDF (it starts at page 37)
JI Shu'an, JI Qiang (2007) Jinfengopteryx Compared to Archaeopteryx, with Comments on the Mosaic Evolution of Long-tailed Avialan Birds In: Acta Geologica Sinica Vol. 81(3), p. 337–343 online
Turner, Makovicky and Norell (2012) A review of dromaeosaurid systematics and paravian phylogeny. In: Bulletin of the American Museum of Natural History. 371, p. 1–206. PDF download link
Lü, J.?C., Xu, L., Liu, Y.?Q., Zhang, X.?L., Jia, S.H., and Ji, Q. (2010) A new troodontid theropod from the Late Cretaceous of central China, and the radiation of Asian troodontids. In: Acta Palaeontologica Polonica 55 (3): 381–388. PDF
Darren Naish (2011) Glorified dinosaurs: the origin and early evolution of birds In: Historical Biology: An International Journal of Paleobiology 23(4), p. 435-438, doi:10.1080/08912963.2010.530761
Lindsay E. Zanno, David D. Gillette, L. Barry Albright and Alan L. Titus (2009) A new North American therizinosaurid and the role of herbivory in ‘predatory’ dinosaur evolution Proc. R. Soc. B 276, p. 3505–3511 doi:10.1098/rspb.2009.1029
Footnotes:
[1] Ji Qiang (2008) p. 38 (according to the listing in the PDF, not in the original article)
[2] JI Shu'an, JI Qiang (2007) p. 337
[3] Turner, Makovicky and Norell (2012) p. 105
[4] Darren Naish (2011) p. 437
[5] Junchang Lü et al. (2010) p. 386
[6] Lindsay E. Zanno p. 3508
[7] JI Shu'an, JI Qiang (2007) p. 338
[8] Turner, Makovicky and Norell (2012) p. 106
[9] Turner, Makovicky and Norell (2012) p. 107