Psilopterus bachmanni (Moreno &

Alvarenga, Herculano M. F. & Höfling, Elizabeth, 2003, Systematic Revision Of The Phorusrhacidae (Aves: Ralliformes), Papéis Avulsos de Zoologia 43 (4), pp. 55-91 : 80-81

Psilopterus bachmanni (Moreno &

Mercerat, 1891) comb. n.

Patagornis bachmanni Moreno & Mercerat, 1891 (pp. 24 and 58).

Ilustrations – Sinclair & Farr (1932) and Moreno & Mercerat (1891).

Remarks – Patagornis bachmanni has priority over Psilopterus communis (both of Moreno & Mercerat, 1891). Psilopterus minutus Ameghino, 1981 , dealt with as a separate species by Brodkorb (11967), is represented only by an incomplete tarsometatarsus, inseparable from P. bachmanni (v. Sinclair & Farr, 1932:188).

Psilopterus communis Moreno & Mercerat, 1891 (pp. 26 and 68); Brodkorb, 1967.

Psilopterus intermedius Moreno & Mercerat, 1891 (pp. 26 and 68); Brodkorb, 1967 (syn. of P. communis ).

Phororhacos delicatus Amegino, 1891; Brodkorb, 1967, (syn. of P. communis ).

Pelecyornis pueyrredonensis Sinclair & Farr, 1932 ; Brodkorb 1967 (syn. of P. communis ).

Lectotype – (by present designation): proximal portion of the left tarsometatarsus (MLP-168).

Hypodigm – lectotype. A proximal and a distal portion of a femur (MLP-165-166) and a distal portion of the tibiotarsus, all of the left side (MLP-167), which appear to be associated to the lectotype. An almost complete skeleton (PUM-15.904), described and pictured by Sinclair & Farr (1932).

Horizon and Locality – Middle Miocene (Santacrucian) of Argentina, Santa Cruz Province: Santa Cruz, Lake Pueyrredon , Monte Observación, La Cueva .

Diagnos i s Revised – Perhaps the smallest of all the known Phorusrhacidae ( Fig. 1E ), estimated at being between 70 to 80 centimeters high, rivalling only Psilopterus affinis in size. Relatively low skull and upper maxilla, in height ( Fig. 26I ), presenting a certain similarity with the Mesembriornithinae . Differences with P. lemoinei as to the different segments of the skeleton are well described by Sinclair & Farr (1932). A peculiarity of P. bachmanni is to be found in the extremely slanted rostral edge of the antorbital fenestra, very different from P. lemoinei ( Figs. 26G and 26I ).

Measurements – Table 8 and Sinclair & Farr (1932).

Figures

FIGURE 1. Reproduction (by E. Brettas) of some Phorusrhacidae keeping the due proportion as to size. The silhouette of a man 1.75 m high is used as a scale. A - Brontornis burmeisteri; B - Paraphysornis brasiliensis; C - Phorusrhacos longissimus; D - Andalgalornis steuletti; E - Psilopterus bachmanni; F - Psilopterus lemoinei; G - Procariama simplex; H - Mesembriornis milneedwardsi.

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).