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The Early Cretaceous II - Mongolia and North China
Jehol Group
Saurischia
Theropoda Tetanurae Arctometatarsalia Troodontia Sinornithoides youngi - Mongolia
Ornithomimosauria Gallimimus bullatus - Mongolia
1. three-toed foot
2. digits IV and V lost on hand
3. long arms
4. semilunate carpal
5. fused pelvis
6. large hole in lacrimal bone in skull
7. ?no unique derived characters?
8. giant, hook-like claw on digit II of pes
9. flight feathers
10. ?no unique derived characters?
11. proximal half of metatarsal of digit III pinchedTherizinosauria Erlikosaurus - Mongolia Segnosaurus - Mongolia Alxasaurus - China
1. proximal half of metatarsal of digit III pinched
2. enlarged brain and eyes and reduced teeth
3. metacarpals of nearly equal length
4. teeth with large denticles
5. highly reduced forelimbs and large size
? Compsognathus prima (Sinosauropteryx) - Liaoning Province http://www.dinosauria.com/jdp/archie/protosino.html http://www.dinosauria.com/jdp/jdp.htm#sino http://www.dinosauria.com/jdp/archie/sinonews.htm Protarchaeopteryx robusta - Liaoning Province http://www.newscientist.co.uk/ns/970419/archaeop_nf.html Maniraptora Deinonychosauria Deinonychus antirrhopus -Cloverly
1. three-toed foot
2. digits IV and V lost on hand
3. long arms
4. semilunate carpal
5. fused pelvis
6. large hole in lacrimal bone in skull
7. ?no unique derived characters?
8. giant, hook-like claw on digit II of pes
9. flight feathers
10. ?no unique derived characters?
11. proximal half of metatarsal of digit III pinched
12. teeth lost in front of mouth and very large claws on manus
Ornithurae Confuciusornis sanctus - Liaoning Province Carinatae Chaoyangia - Liaoning Province
Confuciusornis sanctus, modified from Hou et al. (1996)
Chaoyangia, modified from Hou et al. (1996)
Thyreophora Ankylosauria Sauropelta - Cloverly Ornithopoda Iguanodontia Tenontosaurus - Cloverly Iguanodon - Wealden and Mongolia? Marginocephalia Yaverlandia Wealden Ceratopsia Psittacosauridae Psittacosaurus mongoliensis - Mongolia Psittacosaurus meileyinggensis - Liaoning Province
1. semilunate carpal
2. giant, hook-like claw on digit II of pes
3. flight feathers
4. no shared derived characters?
5. tail becomes pygostyle
6. elongated digit III or hand
7. enlarged keeled sternum
8. no shared derived characters?
9. loss of teeth
1. cheeks
2. armor
3. armor as plates covering back
4. armor as spikes or plates
5. uneven enamel
6. back part of skull makes shelf
7. rostral bone
8. frill
9. reduced hands
10. domed head
11. jaw joint below tooth row
12. elongate hands
13. prepubic process well developed
14. ridge on teeth
15. reduction in manus digits I and V (and large nares)
16. manus digit 1 spike-like
Ji, Q. and Ji, S., 1996. On discovery of the earliest bird fossil in China and the origin of birds. Chinese Geology 10 (233): 30-33.
Sereno, P. C., Rao C., 1992, Early evolution of avian flight and perching; new evidence from the Lower Cretaceous of China. Science, v. 255, n. 5046, p. 845-848.