[D] Limenavis patagonica [~/~]
Describer
Clarke & Chiappe, 2001
Time
Cretaceous Late Campanian Maastrichtian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Maniraptora Avialae Ornithothoraces Ornithurae
Fossilsite
Allen Formation, Salitral Moreno, 20 km south of General Roca, Province of Rio Negro, Argentina
Info
Holotype
Limenavis patagonica, including associated distal portions of a right wing given brief reference in Chiappe (1992b, 1996a). PVL 4731 consists of a portion of the shaft and distal end of the humerus; proximal and distal ends of the ulna; proximal end of the radius; proximal and distal ends of the carpometacarpus; ventral ramus (crus longus) of the ulnare; radiale; most of the proximal phalanx of digit II including the distal end; and several indeterminate fragments.
The material is generally unabraded but crushed. The radius is cemented to the humerus, partially obscuring its cranial surface. The proximal carpometacarpus distal to the carpal trochlea of the incorporated semilunate carpal is covered by the attached distal end of the ulna, and the ventral surface is partially obscured by the fragment of the ulnare. The radiale is preserved roughly in articulation with the carpal trochlea.
Etymology
Limen, Latin for ‘‘threshhold,’’ avis, Latin for bird, and patagonica, from the provenience of the specimen from northern Patagonia, for the window it offers into the origin of the radiation of the avian crown clade.
Diagnosis
Carinate bird with the attachment of the pars ulnaris of the trochlea humeroulnaris on the proximal ulna developed as a pit-shaped fossa, the location of the pisiform process with its proximal surface at approximately the same level as the proximal surface of metacarpal I, and the scar of the ligamentum collaterale ventrale of the ulna proximodistally elongate, extending down the caudal margin of the brachial impression (23:1).
These autapomorphies, along with the presence of three other characters with restricted distributions: (1) a well-developed tendinal groove on the ulnare, (2) the deep infratrochlear fossa of the carpometacarpus, and (3) the presence of three fossae on the proximal surface of the dorsal supracondylar process of the humerus, provide a unique suite of characters diagnosing Limenavis patagonica.
Clarke & Chiappe, 2001
Time
Cretaceous Late Campanian Maastrichtian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Maniraptora Avialae Ornithothoraces Ornithurae
Fossilsite
Allen Formation, Salitral Moreno, 20 km south of General Roca, Province of Rio Negro, Argentina
Info
Holotype
Limenavis patagonica, including associated distal portions of a right wing given brief reference in Chiappe (1992b, 1996a). PVL 4731 consists of a portion of the shaft and distal end of the humerus; proximal and distal ends of the ulna; proximal end of the radius; proximal and distal ends of the carpometacarpus; ventral ramus (crus longus) of the ulnare; radiale; most of the proximal phalanx of digit II including the distal end; and several indeterminate fragments.
The material is generally unabraded but crushed. The radius is cemented to the humerus, partially obscuring its cranial surface. The proximal carpometacarpus distal to the carpal trochlea of the incorporated semilunate carpal is covered by the attached distal end of the ulna, and the ventral surface is partially obscured by the fragment of the ulnare. The radiale is preserved roughly in articulation with the carpal trochlea.
Etymology
Limen, Latin for ‘‘threshhold,’’ avis, Latin for bird, and patagonica, from the provenience of the specimen from northern Patagonia, for the window it offers into the origin of the radiation of the avian crown clade.
Diagnosis
Carinate bird with the attachment of the pars ulnaris of the trochlea humeroulnaris on the proximal ulna developed as a pit-shaped fossa, the location of the pisiform process with its proximal surface at approximately the same level as the proximal surface of metacarpal I, and the scar of the ligamentum collaterale ventrale of the ulna proximodistally elongate, extending down the caudal margin of the brachial impression (23:1).
These autapomorphies, along with the presence of three other characters with restricted distributions: (1) a well-developed tendinal groove on the ulnare, (2) the deep infratrochlear fossa of the carpometacarpus, and (3) the presence of three fossae on the proximal surface of the dorsal supracondylar process of the humerus, provide a unique suite of characters diagnosing Limenavis patagonica.