Vinchinavis paka gen. et sp. nov. (1 Viewer)

[Fred Ruhe]

Claudia P. Tambussi, Federico J. Degrange, Patricia L. Ciccioli and Francisco Prevosti, 2020

Avian remains from the Toro Negro Formation (Neogene), Central Andes of Argentina

Journal of South American Earth Sciences. in press: Article 102988.
doi:10.1016/j.jsames.2020.102988

Highlights

Avian remains from the late Miocene of Northwestern Argentina are described extensively.

A new genus and species of a large eagle is proposed.

Herbivorous rheids, scavengers condors and zoophagous eagles are represented in the Toro Negro Formation at La Rioja Province.

Palaeoenvironmental considerations from the Toro Negro Formation are made.

Abstract https://www.sciencedirect.com/science/article/abs/pii/S0895981120305319?via=ihub

We describe new avian remains from the lower levels of the Toro Negro Formation (∼7-6 Ma, U–Pb), exposed in Quebrada de la Troya between Vinchina and Jagüé towns in La Rioja Province, Argentina. The Toro Negro Formation is composed of a thick continental sequence (∼2.4 km) of sandstones, conglomerates and mudstones deposited in both fluvial and lacustrine systems at the base of the unit. The avifauna of Toro Negro is low in diversity, and the majority of the remains are fragmentary and isolated. However, it is interesting in that it includes carnivorous birds such as a new species of a large eagle (Vinchinavis paka gen. et sp. nov.), scavengers (condors) and large herbivores (rheas). On the whole, the occurrences documented within the Toro Negro Formation confirm the presence of taxa with strong temperate warm preferences that typically inhabits open areas with arboreal patches within an arid-semiarid zone. The palaeoenvironmental characteristics of the fauna are confirmed as fully compatible with the evidence previously obtained through sedimentology and facies analysis.

Enjoy,

Fred

 

[Fred Ruhe]

SYSTEMATIC PALAEONTOLOGY

All fossil materials described here come from Facies II and III (Ciccioli et al. 2018) in the lower levels of Toro Negro Formation (~7–6 Ma, U-Pb ages, Amidon et al. 2016) exposed at Quebrada de la Troya between the Vinchina and Jagüé localities in La Rioja Province, Late Miocene.

Order RHEIFORMES (Forbes, 1884)
Family RHEIDAE Bonaparte, 1849
Genus OPISTHODACTYLUS Ameghino, 1891
Opisthodactylus cf. kirchneri Noriega et al., 2017

Material. MLP 68-III-14-2, distal end of right tibiotarsus.

Description and comparisons. Dimensions are intermediate between those of Opisthodactylus kirchneri Noriega et al. and those of Pterocnemia and Rhea (excluding Hinasuri nehuensis Tambussi of which the tibiotarsus is not known). In cranial view, the sulcus extensorius is markedly excavated and very well delimited, similar to the condition observed in Opisthodactylus patagonicus Ameghino, O. kirchneri, Pterocnemia pennata, and P. mesopotamica Agnolín & Noriega, and different from that of Rhea americana. Its distal portion is extended distally in such a way that it resulted in the separation of the attachment of the internal ligament and the ligamentum transversum (Fig. 3E) as observed in R. americana (Tambussi & Tonni 1985; Noriega et al. 2017), contrasting with O. patagonicus, O. kirchneri, P. pennata, and P. mesopotamica where both attachments are connected. The combination of these characteristics (i.e., deep sulcus extensorius and the discontinuity between the attachments), would be unique to the Toro Negro specimen within known rheiforms. According to Noriega et al. (2017) in their description of O. kirchneri, this zone is broken in the holotype although they assume the presence of continuity. The trochlea cartilaginis tibialis narrows cranially and distally and the medial margin curves medially. In caudal aspect, the trochlea cartilaginis tibialis is not delimited proximally by a well-marked horizontal ridge as seen in R. americana. The medial ligamentary ridge is sharp, similar to that of O. patagonicus and O. kirchneri, and continues distally until reaching the internal ligamental prominence on the medial side of condylus medialis. In lateral aspect, the surface of the diaphysis is badly crushed, the tuberculum retinaculi m. fibularis is not preserved, and the area of the sulcus m. fibularis is broken. The depressio epicondylaris lateralis is deep (but less than R. americana), and the edge of the condylus lateralis is subcircular without a marked posterior notch (unlike R. americana). The epicondylus medialis in medial aspect is less prominent, and the depressio condylaris medialis is less excavated than in Rhea, similar to Pterocnemia sp. and P. pennata (see Agnolín & Noriega 2012; Tambussi & Tonni 1985). The condylar ridges are less thick than in Rhea. In caudal view, the intercondylar space is wide.

 

[Fred Ruhe]

Order CATHARTIFORMES Coues, 1894
Family CATHARTIDAE Lafresnaye, 1839

Material and provenience. CRILAR Pv-TN 9-2017, left ungual phalanx, Toro Negro Formation, Facies III, near Vinchina town, La Rioja Province, Argentina, 28° 41′ 32.9″ S, 68° 18′ 22.8″ W.

Description and comparisons. The presence of a stout, wide and caudally directed tuberculum flexorium, together with the absence of lateral grooves indicate that CRILAR Pv-TN 9-2017 can be referred to Cathartiformes. We based our assessment of the general morphology and digit identity on Mosto & Tambussi (2014) and comparisons with bones of the Andean condor Vultur gryphus and accipitrids. As it is pointed out by Mosto & Tambussi (2014), accipitrids (and falconids) shows two wellmarked edges that delimit the ventral surface of the phalanx. In the ungual of Toro Negro these ridges do not exist. In accipitrids, the ungual phalanx of digit 4 is generally characterized by symmetry whereas that of digit 3 presents a medial edge, absent in the phalanx of Toro Negro.
In the material CRILAR Pv-TN 9-2017, the articular facet is moderately symmetrical; the lateral and medial cotylae have a similar distal extension. The medial cotyla is deeper than the lateral one; its medial margin is concave dorsally. The tuberculum extensorium is inconspicuous. The tuberculum flexorium is massive, distally oriented; a well-marked groove of dorsal position and ventral to the middle prominence, furrows the tuberculum flexorium lateromedially. A dorsoventral ridge separates the lateral and medial sides of the tubercle, both sides being slightly excavated. The middle prominence is laterally displaced as occurs in the talons of most Accipitridae. No ventral foramina are visible. A short proximodistal furrow is exposed on the lateral surface of the talon. In its most distal portion, a conspicuous foramen is located.

 

[Fred Ruhe]

Aves INCERTI ORDINIS

Material and provenience. PULR-V 131, portion of the corpus of a cervical vertebra, Facies III, 28° 41´ 23″ S, 68° 18´ 09″ W.

Remarks. The morphology roughly resembles that of Cathartiformes, but the material is heavily eroded, limiting precise identification.

Order ACCIPITRIFORMES Voous, 1973
Family ACCIPITRIDAE Vieillot, 1816
Genus VINCHINAVIS nov.

Derivation of name. Relative to Vinchina valley, where the Toro Negro Formation is exposed; Avis is Latin for bird.

Type and only known species. Vinchinavis paka sp. nov.

Diagnosis. As for the type and only species.

Vinchinavis paka sp. nov.

Derivation of name. The species name is after “paka”, meaning eagle in quechua, reflecting its proposed affinities to the eagles. Quechua was the language of the Capayanos who were part of the largest settlement in the Vinchina area. Towards the end of the 18h century, the government forced the use of Spanish and Quechua fell into disuse. Taken from Quechua Dictionary available at https://www.inkatour.com/dico

Holotype. PULR-V 130, left ulna and radius lacking the proximal ends.

Locality and Horizon. Toro Negro Formation, Facies III, 150 m from the road, on the left side of the route from Vinchina to Jagüé, 28° 42´ 03″ S, 68° 18´19″ W.

Diagnosis. A large raptor with the following combination of features: condylus dorsalis ulnae flattened, condylus ventralis ulnae and condylus dorsalis ulnae equally projected distally, absence of foramen at the distal end of the ulna, radius with facies articularis ulnaris flanked by a well-marked ridge extended proximally, long and deep sulcus tendinosus limited by marked ridges, presence of a second and shorter groove running between the sulcus tendinosus and the margin of the shaft, shallow depressio ligamentosa, presence of a well-marked tubercle proximally to the depressio ligamentosa (corresponding to a scar of the lig. interosseum radiocarpale distale).

Description and comparison. The new taxon shares with the Accipitridae the presence of a proximally elongated condylus dorsalis ulnae, a shallow depressio ligamentosa and a continuous ventral tuberculum aponeurosis with the facies articularis radiocarpalis. The holotype, PULR-V 130 (Fig. 1), shows significant morphological variations with other large eagles. The absence of a pneumatic foramina in the depressio ligamentosa of the radius indicates that PULR-V 130 is not assignable to Cathartidae. The preserved ulnar shaft of the new taxon is robust, straight (curved in Accipiter), and has an elliptical cross-section that bends slightly ventrally. There is no evidence of a foramen in the incisura tuberculi carpalis. The tuberculum carpale is not preserved. The condylus ventralis ulnae is rounded and projects distally to the same level as the condylus dorsalis ulnae (more extended distally in Aquila, Haliaeetus and Circus). This condition is shared with Geranoaetus melanoleucus, but not with Buteogallus coronatus and Elanus leucurus in which it is flattened and broad. The condylus dorsalis ulnae is robust, strongly extended ventrally and also extended only slightly proximally. Its external ridge is marked and rounded. These features discourage the assignation to Geranoaetus, Halieetus and Spizaetus, in which the condylus dorsalis ulnae has a larger proximal extension (especially in the later), and also to Buteogallus which has a poorly developed ventrally condylus, and to Accipiter which has a pointed external ridge of the condylus. On the dorsolateral surface of the condylus, there is a shallow rounded pit. This scar is elongated and very well marked in other large eagles such as Geranoaetus and Buteogallus. The depressio radialis is deep as in B. coronatus (shallow in G. melanoleucus). Five ventral papillae remigales are visible and separated from each other by about 15 mm. Only two dorsal papillae remigales can be identified The number of caudal and ventral papillae remigales seems to indicate that there were few secondary remiges.
The shaft of the radius of V. paka has an elliptical cross-section (more flattened in B. coronatus); the preserved section is slightly curved laterally and dorsally. In ventral view, the depressio ligamentosa is shallow. The facies articularis ulnaris extends from the ventro-lateral surface around the medial margin, where it is flanked by a wellmarked ridge (more marked than B. coronatus and G. melanoleucus) that continues proximally and dorsally. In dorsal view, the sulcus tendinosus is very well-marked, wide and deep (deeper in Accipiter), extending about 3 cm towards the proximal area through a single groove limited by marked ridges, especially the lateral one. Distally, it widens and forms an excavated fossa. Another small parallel groove (shorter than the sulcus tendinosus) is delimited between this lateral prominent ridge and the lateral margin of the shaft. This character seems to be exclusive to Vinchinavis paka. In both B. coronatus and G. melanoleucus, the area corresponding to this groove is smooth. Although somewhat eroded, it can be inferred that the tuberculum aponeurosis ventralis, thinner than that of Spizaetus, is continuous with the facies articularis radiocarpalis, and endowed with a very well-marked scar dorsally. The facies articularis radiocarpalis is rounded and thick (thinner in Buteo), with a smooth surface, not exhibiting sharp limits with the diaphysis towards the ventral side as in Buteogallus. Intermuscular lines are not visible.

Fred

Fig. 1. Vinchinavis paka nov. gen. et sp., PULR-V 13-1998, holotype, left ulna (A-E) and radius (F-J) in dorsal (A, F), lateral (B, G), ventral (C, H), medial (D, I), and distal (E, J) views. Abbreviations: cdu, condylus dorsalis ulnaris; cvu, condylus ventralis ulnaris; dl, depression ligamentosa; dr, depression radialis; far, facies articularis radiocarpalis; fau, facies articularis ulnaris; prc, papillae remigales caudales; prv, papillae remigales ventrales; st, sulcus tendinosus; tav, tuberculum aponeurosis ventralis. Scale bar equals 1 cm. (color only in the online version)

 

[l_raty]

Is this journal printed ?

(Elsevier does not appear to offer any kind of subscription; the only thing an individual can apparently do to obtain the paper is to buy the individual pdf file.
Pagination ceased to be continuous within volumes in the middle of 2019; non-continuous pagination is unusual in a printed journal volume.
There is no ZooBank registration info in the paper so far as I can find.)

 

[Fred Ruhe]

Is this journal printed ?

(Elsevier does not appear to offer any kind of subscription; the only thing an individual can apparently do to obtain the paper is to buy the individual pdf file.
Pagination ceased to be continuous within volumes in the middle of 2019; non-continuous pagination is unusual in a printed journal volume.
There is no ZooBank registration info in the paper so far as I can find.)

This is a "journsl pre-proof". I don't know whether the ZooBank registration can be added in the final version?

I also don't know whether the journal is printed or not.

Fred

 

[l_raty]

This is a "journsl pre-proof". I don't know whether the ZooBank registration can be added in the final version?

In principle, yes. But, if it's not there, it means that the authors did not care about it, and most journals don't either -- so I wouldn't be confident that it will happen. (A few journals which specialize on taxonomy and nomenclature register *all* the paper they publish with ZooBank. But this does not seem to be the case here.)

(Registration data can be added at any point in the publication process, even after a pdf presented as "final" has been produced: if a new pdf, differing only in the registration data having been added to it, is then issued by the publisher, this last pdf will be published for nomenclature purposes, and a name might be available from it. This was done, for example, for Myrmoderus eowilsoni: [this pdf], "published December 13, 2017" without ZooBank registration, was unpublished; it was replaced with [this one], "published January 28, 2018" with ZooBank registration. (Which should be OK if [the entry in ZooBank] did "give the name and Internet address of an organization other than the publisher that is intended to permanently archive the work in a manner that preserves the content and layout, and is capable of doing so"... Which does not seem to be the case.))