[D] Epidendrosaurus ningchengensis [~/~]
Describer
Zhang, Zhou, Xu & Wang, 2002
Time
?Jurassic Late
Classification
Saurischia Theropoda Tetanurae Coelurosauria Maniraptora Avialae Incertae Sedis [Scansoriopterygidae]
Diet
Carnivore
Fossilsite
Daohugou Formation, Inner Mongolia (Nei Monggol AR), Daohugou, China
Info
Genus - Typespecies
IVPP V12653 [juv.] Nearly complete skeleton of juvenile individual.
Hypodigm APK:100/95: Holotype skeleton only.
E. ningchengensis is an unequivocal arboreal coelurosaur, This juvenile coelurosaur\\\'s third manual digit is extremely elongated, distinctively different from that of other known dinosaurs and birds. It represents certainly a type of adaptation previously unreported from the Mesozoic although the exact function of the third manual digit is unclear. The relatively long forelimb, penultimate phalanx of manual digit II, and pedal penultimate phalanges, are interpreted as evidence for the arboreal habit of Epidendrosaurus. Because Epidendrosaurus is more similar to advanced birds in some arboreal features than to Archaeopteryx, the authors suggest that the initial appearance of tree-adaptation in theropods was probably not directly related to flight but to other functions, such as seeking food or escaping from predators.
Ethymology
Greek epi = \\\"upon\\\"+ Greek dendron = \\\"tree\\\" + Greek sauros = \\\"lizard\\\"
Epidendrosaurus ningchengensis is possible a junior synonym of Scansoriopteryx heilmanni (Czercas and Yuan, 2002)
Zhang, F., Zhou, Z., Xu, X. and Wang, X. (2002) A juvenile coelurosaurian theropod from China indicates arboreal habits Naturwissenschaften, DOI 10.1007/s00114-002-0353-8 [online publication]
Abstract
Here we report an unequivocal arboreal coelurosaur, Epidendrosaurus ningchengensis gen. et sp.nov. This juvenile coelurosaur\\\'s third manual digit is extremely elongated, distinctively different from that of other known dinosaurs and birds. It represents certainly a type of adaptation previously unreported from the Mesozoic although the exact function of the third manual digit is unclear. The relatively long forelimb, penultimate phalanx of manual digit II, and pedal penultimate phalanges, are interpreted as evidence for the arboreal habit of Epidendrosaurus. Because Epidendrosaurus is more similar to advanced birds in some arboreal features than to Archaeopteryx, we suggest that the initial appearance of tree-adaptation in theropods was probably not directly related to flight but to other functions, such as seeking food or escaping from predators. ..
Description
The specimen is about the size of a house sparrow (Passer domesticus) and obviously a juvenile individual as evidenced by many distinctive juvenile features, such as the incomplete ossifications of articular surface, presence of grooves on some limb bones and less well- defined extremities of postcranial long bones... Taxonomy Theropod Marsh, 1881 Coelurosauria Huene, 1914 Maniraptora Gauthier, 1986 Epidendrosaurus ningchengensis gen. et sp. nov.
Etymology
The generic name is derived from the obvious arboreal adaptation of this animal, the specific name from the locality Ningcheng County of Nei Mongol. Holotype IVPP (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China) collection number V12653.
Locality and horizon
Daohugou, Ningcheng County, East of Nei Mongol. Daohugou Formation, (?) Late Jurassic (Zhang 2002 )
Diagnosis
Manual digit III elongated, nearly twice as long as digit II. Metacarpals II and III short, about 30% of the length of humerus. Second phalanx of manual digit II long, nearly 170% the length of the first phalanx (see electronic supplementary material S1). Description The frontal and parietal are similar to those of dromaeosaurs, such as Sinornithosaurus (Xu et al. 1999 ), and the basal bird Archaeopteryx (Elzanowski and Wellnhofer 1996 ; Martin and Zhou 1997 . The frontals are probably only slightly fused near the caudal region . However, the two parietals appear to be completely fused as in Sinornithosaurus. There are at least 12 teeth in the mandible.
The teeth progressively decrease in size caudally and are sparsely distributed as in most early birds including Archaeopteryx. The jaws are wide. The two mandibles are tightly contacted at the anterior end, yet it is difficult to determine whether they are fused. Among non-avian theropods, only oviraptorids have fused mandibular symphysis. There are at least nine cervical vertebrae preserved in articulation, with the anterior ones longer than the posterior. The total length of the tail is estimated to be 6-7 times as long as the femur .Near the distal end of the tail, integumentary imprints are faintly preserved, resembling those of Microraptor (Xu et al. 2000 ). The scapula has a primitive expanded distal end (Currie and Padian 1997 ).
The coracoid is generally similar to that of some advanced non-avian coelurosaurs (Currie and Padian 1997) and Archaeopteryx (Ostrom1976) > (Wellnhofer 1992 ). The ulna is posteriorly bowed and slightly wider than the radius. The manus is considerably longer than the humerus. Metacarpals II and III are comparatively short and only about one-third the length of the humerus. The first phalanx of digit II is shorter than the second, as in some other coelurosaurian dinosaurs (Currie and Padian 1997 ) and the basal birds Archaeopteryx ..., Confuciusornis...and Protopteryx; the reverse is true in more advanced birds such as Sinornis (Sereno and Rao 1992) and Cathayornis (Zhou 1995).
One of the most distinctive features of the hand of Epidendrosaurus is the extremely elongated digit III; it is nearly twice the length of digit II, differing from all other known dinosaurs and birds (Currie and Padian 1997) . The hindlimb is slightly shorter than the forelimb mainly because of the extremely elongated manual digit III. The femur is shorter than the humerus. Metatarsal IV is slightly shorter than both II and III. Metatarsal I is attached to the distal end of metatarsal II. Distally the trochlea of metatarsal I aligns with those of II and III as in advanced perching birds, but not in other known dinosaurs.
The pedal digits are relatively short. Among the four pedal digits, IV is longer than II and closer to III in length. The penultimate phalanges of digits III and IV are markedly longer than the neighboring proximal phalanges, whereas in digit II the second phalanx is only slightly longer than the first. Digit I is relatively long, and distally it reaches the middle of the second phalanx of digit III.
Zhang, Zhou, Xu & Wang, 2002
Time
?Jurassic Late
Classification
Saurischia Theropoda Tetanurae Coelurosauria Maniraptora Avialae Incertae Sedis [Scansoriopterygidae]
Diet
Carnivore
Fossilsite
Daohugou Formation, Inner Mongolia (Nei Monggol AR), Daohugou, China
Info
Genus - Typespecies
IVPP V12653 [juv.] Nearly complete skeleton of juvenile individual.
Hypodigm APK:100/95: Holotype skeleton only.
E. ningchengensis is an unequivocal arboreal coelurosaur, This juvenile coelurosaur\\\'s third manual digit is extremely elongated, distinctively different from that of other known dinosaurs and birds. It represents certainly a type of adaptation previously unreported from the Mesozoic although the exact function of the third manual digit is unclear. The relatively long forelimb, penultimate phalanx of manual digit II, and pedal penultimate phalanges, are interpreted as evidence for the arboreal habit of Epidendrosaurus. Because Epidendrosaurus is more similar to advanced birds in some arboreal features than to Archaeopteryx, the authors suggest that the initial appearance of tree-adaptation in theropods was probably not directly related to flight but to other functions, such as seeking food or escaping from predators.
Ethymology
Greek epi = \\\"upon\\\"+ Greek dendron = \\\"tree\\\" + Greek sauros = \\\"lizard\\\"
Epidendrosaurus ningchengensis is possible a junior synonym of Scansoriopteryx heilmanni (Czercas and Yuan, 2002)
Zhang, F., Zhou, Z., Xu, X. and Wang, X. (2002) A juvenile coelurosaurian theropod from China indicates arboreal habits Naturwissenschaften, DOI 10.1007/s00114-002-0353-8 [online publication]
Abstract
Here we report an unequivocal arboreal coelurosaur, Epidendrosaurus ningchengensis gen. et sp.nov. This juvenile coelurosaur\\\'s third manual digit is extremely elongated, distinctively different from that of other known dinosaurs and birds. It represents certainly a type of adaptation previously unreported from the Mesozoic although the exact function of the third manual digit is unclear. The relatively long forelimb, penultimate phalanx of manual digit II, and pedal penultimate phalanges, are interpreted as evidence for the arboreal habit of Epidendrosaurus. Because Epidendrosaurus is more similar to advanced birds in some arboreal features than to Archaeopteryx, we suggest that the initial appearance of tree-adaptation in theropods was probably not directly related to flight but to other functions, such as seeking food or escaping from predators. ..
Description
The specimen is about the size of a house sparrow (Passer domesticus) and obviously a juvenile individual as evidenced by many distinctive juvenile features, such as the incomplete ossifications of articular surface, presence of grooves on some limb bones and less well- defined extremities of postcranial long bones... Taxonomy Theropod Marsh, 1881 Coelurosauria Huene, 1914 Maniraptora Gauthier, 1986 Epidendrosaurus ningchengensis gen. et sp. nov.
Etymology
The generic name is derived from the obvious arboreal adaptation of this animal, the specific name from the locality Ningcheng County of Nei Mongol. Holotype IVPP (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China) collection number V12653.
Locality and horizon
Daohugou, Ningcheng County, East of Nei Mongol. Daohugou Formation, (?) Late Jurassic (Zhang 2002 )
Diagnosis
Manual digit III elongated, nearly twice as long as digit II. Metacarpals II and III short, about 30% of the length of humerus. Second phalanx of manual digit II long, nearly 170% the length of the first phalanx (see electronic supplementary material S1). Description The frontal and parietal are similar to those of dromaeosaurs, such as Sinornithosaurus (Xu et al. 1999 ), and the basal bird Archaeopteryx (Elzanowski and Wellnhofer 1996 ; Martin and Zhou 1997 . The frontals are probably only slightly fused near the caudal region . However, the two parietals appear to be completely fused as in Sinornithosaurus. There are at least 12 teeth in the mandible.
The teeth progressively decrease in size caudally and are sparsely distributed as in most early birds including Archaeopteryx. The jaws are wide. The two mandibles are tightly contacted at the anterior end, yet it is difficult to determine whether they are fused. Among non-avian theropods, only oviraptorids have fused mandibular symphysis. There are at least nine cervical vertebrae preserved in articulation, with the anterior ones longer than the posterior. The total length of the tail is estimated to be 6-7 times as long as the femur .Near the distal end of the tail, integumentary imprints are faintly preserved, resembling those of Microraptor (Xu et al. 2000 ). The scapula has a primitive expanded distal end (Currie and Padian 1997 ).
The coracoid is generally similar to that of some advanced non-avian coelurosaurs (Currie and Padian 1997) and Archaeopteryx (Ostrom1976) > (Wellnhofer 1992 ). The ulna is posteriorly bowed and slightly wider than the radius. The manus is considerably longer than the humerus. Metacarpals II and III are comparatively short and only about one-third the length of the humerus. The first phalanx of digit II is shorter than the second, as in some other coelurosaurian dinosaurs (Currie and Padian 1997 ) and the basal birds Archaeopteryx ..., Confuciusornis...and Protopteryx; the reverse is true in more advanced birds such as Sinornis (Sereno and Rao 1992) and Cathayornis (Zhou 1995).
One of the most distinctive features of the hand of Epidendrosaurus is the extremely elongated digit III; it is nearly twice the length of digit II, differing from all other known dinosaurs and birds (Currie and Padian 1997) . The hindlimb is slightly shorter than the forelimb mainly because of the extremely elongated manual digit III. The femur is shorter than the humerus. Metatarsal IV is slightly shorter than both II and III. Metatarsal I is attached to the distal end of metatarsal II. Distally the trochlea of metatarsal I aligns with those of II and III as in advanced perching birds, but not in other known dinosaurs.
The pedal digits are relatively short. Among the four pedal digits, IV is longer than II and closer to III in length. The penultimate phalanges of digits III and IV are markedly longer than the neighboring proximal phalanges, whereas in digit II the second phalanx is only slightly longer than the first. Digit I is relatively long, and distally it reaches the middle of the second phalanx of digit III.