Andrewsornis abbotti Patterson, 1941

Alvarenga, Herculano M. F. & Höfling, Elizabeth, 2003, Systematic Revision Of The Phorusrhacidae (Aves: Ralliformes), Papéis Avulsos de Zoologia 43 (4), pp. 55-91 : 78-79

Andrewsornis abbotti Patterson, 1941

Type – Incomplete skull, mandible ( Fig. 26A ), omal extremity of a coracoid, the second and ungual phalanges of digit II ( FM-P13417 ) .

Hypodigm – Type; a mandibular symphysis ( FM-P13383 ) ( Figs. 25A, 25B and 25C ); a left femur with only the internal condyle missing ( FM-P14678 ) ( Figs. 25D, 25E and 25F ) .

Horizon and Locality – Middle and Upper Oligocene of Argentina, (Deseadan); Cabeca Blanca (Chubut), Pico Truncado (Santa Cruz) .

Measurements – Table 7; Patterson, (1941).

Illustrations – Patterson (1941).

Remarks – The mandibular symphysis of specimen FM-P 13383 ( Figs. 25A, 25B and 25C ), is smaller than that of the type specimen and the femur ( FM-P 14678) ( Figs. 25D, 25E and 25F ) is still smaller than the corresponding bone of Patagornis marshi . However, the measurements of the type specimen lead one to believe it to have been a larger bird. This is certainly one more example of intraspecific variation in these birds, and possibly even sexual dimorphism. A phalanx of digit II (MACN-A-52-110), whereon Ameghino (1898) described Aucornis solidus , is very probably attributed to this species and the name of which naturally could have priority. However, the diagnostic value of this phalanx is very debatable, as also one can question the correct geographical and stratigraphical origin of the specimen as well. It is thus preferable in this case to consider Aucornis solidus Ameghino, 1898 as a species inquirenda.

Figures

FIGURE 25. Andrewsornis abbotti. Mandibular symphysis (FM-P13383), from Pico Truncado, Rio Deseado, Province of Santa Cruz, Argentina: A - left lateral, B - dorsal and C - ventral, views. Left femur (FM-P14678): D - dorsal, E - lateral and F - ventral, views.

FIGURE 26. Skulls of the Patagornithinae (A-C), Mesembriornithinae (D) and Psiloterinae (E-J). A - Andrewsornis abbotti (FM-P13417; from Patterson, 1941), B - Patagornis marshi (BMNH-A-516; from Andrews, 1899), C - Andalgalornis steulleti (FM-P14357); D - Mesembriornis milneedwardsi (MMP-S155); E - Procariama simplex (FM-P14525); F - Psilopterus lemoinei (FM-P13257); G - Psilopterus lemoinei (PUM-15402); H - Psilopterus lemoinei (AMNH-9157); I - Psilopterus lemoinei (PUM-15109); J - Psilopterus bachmanni (PUM-15904). G-J inverted figures from Sinclair & Farr (1910).