Freak Felids - A Discussion of History's Largest Felines

[Acinonyx sp.]

Not one of the largest but large regardless


The Iberian record of the puma-like cat Puma pardoides (Owen, 1846) (Carnivora, Felidae)

Abstract 
Fossil puma-like cats (Puma pardoides) are recorded from several Late Pliocene to Early Pleistocene Eurasian localities, but the interpretation of the phylogenetic relationships between them and the extant puma (Puma concolor) remains controversial. In the past, extinct puma-like cats have been classified into several genera and species, and a close relationship with both pumas (Puma concolor) and snow leopards (Uncia uncia) has been suggested. Here, we describe the fossil remains of puma-like cats from the Iberian Peninsula. These remains (from the localities of La Puebla de Valverde, Cueva Victoria and Vallparadís) cover the whole known chronological distribution of this species in Eurasia. Although there are dentognathic similarities with U. uncia, the Iberian remains of P. pardoides most closely resemble the extant P. concolor. It is concluded that P. pardoides is closely related to living pumas, which supports a likely Eurasian origin of the puma lineage.

1. Introduction 
Pumas (also known as cougars or mountain lions) are classified into the species Puma concolor (Linnaeus, 1771), which is distributed though the American continent. Nonetheless, there are also puma-like fossil remains recorded throughout Eurasia (Hemmer et al., 2004), which following Hemmer (2001), we attribute to Puma pardoides (Owen, 1846) (Owen, 1846)—although in the past, they were generally attributed to Panthera schaubi Viret, 1954 (Viret, 1954), and even a new genus, Viretailurus Hemmer, 1964 (Hemmer, 1964), was erected on their basis. Unfortunately, these remains are very scarce, so that the anatomy of these middle-sized carnivores is poorly known and its phylogenetic status (and, by implication, taxonomic attribution) remains uncertain. Following Wilson and Reeder (Wilson and Reeder, 2005), we include the genus Puma Jardine, 1834 in the subfamily Felinae, although other authors include it into the Pantherinae (Wilson and Reeder, 2005). In this article, we describe the unpublished dentognathic remains of P. pardoides from the Spanish Early Pleistocene sites of Cueva Victoria and Vallparadís, as well as the mandibular and postcranial remains from the Late Pliocene of La Puebla de Valverde (which had been previously mentioned, but not figured or described in detail (Kurtén and Crusafont-Pairó, 1977)). Besides providing a detailed comparison with extant pumas, we also compare this fossil material with extant snow leopards, Uncia uncia (Schreber, 1775), given the fact that similarities with this species have been noted in some puma-like fossil material from Saint-Vallier (Olive, 2006). Finally, the implications of Eurasian puma-like cats for the understanding of the origins of extant pumas are also discussed from a paleobiogeographic viewpoint.

3. Systematic palaeontology 

*This image is copyright of its original author

Measurements:

*This image is copyright of its original author

Fossil Remains:

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

4. Discussion 4.1. 
Taxonomic remarks 
Until recently, Eurasian puma-like fossil remains were still attributed to P. schaubi (Turner and Antón, 1997), which was originally described on the basis of material Saint-Vallier (France; ca. 2.1 Ma) (Viret, 1954). Soon later, however, Hemmer (1964) showed that this material was clearly not pantherine, but displayed many shared features with the American puma, and on this basis erected the genus Viretailurus. Further similarities in dental dimensions and the position of mental foramina between this species and fossil American pumas were remarked by Kurtén (1976), while Sotnikova (1976) similarly noted that the material from Central Asia attributed to Felis (Puma) sp. also displayed similarities with this European species. It was not until the paper by Kurtén and Crusafont-Pairó (1977), describing the carnivore remains from La Puebla de Valverde, that the similarities between the above-mentioned species and Felis pardoides Owen (1846), originally described from the English Red Crags, were noticed. Most recently, Hemmer (2001) described the puma-like remains from the Epivillafranchian of Untermassfeld, and concluded that Viretailurus Hemmer, 1964 and Panthera schaubi Viret, 1954 were junior subjective synonyms of Puma Jardine, 1834 and Puma pardoides (Owen, 1846), respectively.

4.2. The Eurasian record of puma-like cats 
In the Iberian Peninsula, P. pardoides is first recorded at the MN17 locality of La Puebla de Valverde (Kurtén and Crusafont-Pairó, 1977), on the basis of the remains described in this paper. P. pardoides is also recorded in the Early Pleistocene site of Cueva Victoria (ca. 1.1 Ma, according to (Blain et al., 2008) and references therein). Finally, as shown in this paper, P. pardoides is also recorded from the late Early Pleistocene site of Vallparadís in Terrassa (Barcelona, Spain; (Alba et al., 2008)). An estimated age of more than 0.8 Ma has been proposed for this locality (Alba et al., 2008), so that it might represent the youngest citation of this species from the Iberian Peninsula. P. pardoides had not yet been recognized from the Vallparadís assemblage when the preliminary faunal list from this locality was published (Alba et al., 2008). Outside of the Iberian Peninsula, P. pardoides is recorded from the MN16b of Perrier-Étouaires (Hugueney et al., 1989) and the MN17 of Saint-Vallier (Vislobokova et al., 1993; Argant, 2004) in France; the MN16b or MN17 locality of Newborn, Red Crags in Great Britain (Owen, 1846; Hemmer et al., 2004); Untermassfeld (above the base of the Jaramillo chron, ca. 1 Ma) in Germany (Hemmer, 2001); probably Stránská skála (late Early Pleistocene) in the Czech Republic (Hemmer, 2001); possibly from the MN17 locality of Varshets in Bulgaria (Spassov, 2000); the MN16 site of Kvabebi in Georgia (Hemmer et al., 2004); and the Early Villafranchian localities of Shamar and Beregovaya in Mongolia (Sotnikova, 1976), which respectively correspond to the MN16a and MN16b (Vislobokova et al., 1993). Additional puma-like fossil remains have been described from the localities of Vallonnet (Jaramillo chron, ca. 1 Ma) (Moullé, 1992) in France and Tegelen (MN17) in The Netherlands (Hemmer, 2001), although their attribution to P. pardoides remains doubtful (Moullé et al., 2006; O’Regan and Turner, 2004). Recently, Petrucci (Petrucci, 2008) has noted that an ulna and a fifth metacarpal from the Early Pleistocene locality of Pirro Nord in Italy resemble puma-like cats in both size and morphology, although he formally attributes them to “Felidae indet. (Puma size)”.

3. Attribution of the Iberian material 
The Iberian specimens of P. pardoides from La Puebla de Valverde, Cueva Victoria and Vallparadís display many dentognathic similarities to the extant P. concolor; these include: (1) the location of the three mental foramina; (2) the position of the masseteric fossa, reaching the level of the m1 protoconid; (3) p3 with a well-developed anterior accessory cusp, more protruding than the posterior cusp; (4) p4 with symmetrical protoconid (in lateral view), and well-developed and similarly-sized accessory cusps; and (5) m1 with a protoconid slightly larger and higher than the paraconid, and quite vertically oriented. With regard to the postcranial material, the Iberian fossil remains are almost entirely comparable to extant pumas on morphological grounds, except for a general greater robusticity and a slightly larger size (near the maximum values of the extant species). The Iberian remains described in this paper also display several similarities to extant U. uncia: (1) stoutly-built lower mandibular corpus; (2) number and position of the mental foramina; (3) masseteric fossa reaching the level of the m1 protoconid, in lateral view; (4) p3 with a welldeveloped, circular parastylid that is more protruding than the posterior accessory cuspid; and (5) p4 with a symmetrical protoconid in lateral view and with two well-developed and similarly-sized accessory cuspids. Nevertheless, the Iberian remains further differ from U. uncia by several other features, namely: (1) m1 protoconid slightly larger and more protruding than the paraconid, with a small cuspid at the base of the protoconid and, in some cases, a lingual bulge between the two main cuspids; (2) lower values of the mandibular robusticity index; and (3) relatively short and robust femur. Additional comparisons with Early Pliocene European felids, such as the machairodont Dinofelis Zdansky, 1924, would be interesting, especially given some poscranial similarities—Dinofelis displays a forelimb morphology convergent with that of pantherines (Werdelin and Lewis, 2001). Unfortunately, the scarce European remains of this genus (Werdelin and Lewis, 2001) prevent a correct comparison with the material of P. pardoides reported here. To sum up, the Iberian fossil remains described in this paper displaymany similarities to the extant P. concolor and the fossil P. pardoides from Saint-Vallier, while they can be distinguished from U. uncia on both dental and postcranial grounds. As such, we attribute the puma-like remains described in this paper to P. pardoides, albeit noting that, to some regards, the dental remains from Cueva Victoria and Vallparadís more closely resemble extant pumas than P. pardoides from Saint-Vallier and La Puebla de Valverde.


4.4. Paleobiogeographic implications
 The evolutionary origins of the puma lineage are far from being definitively settled. It has been previously argued that the cheetah-like cat lineage of Miracinonyx Adams, 1979 and the puma lineage might have shared a last common ancestor in the Middle to Late Pliocene of America (Johnson et al., 2006), thus implying an American origin of the genus Puma. However, this is not supported by paleontological evidence, because the fossil record of P. concolor in the American continent begins at around 400 ka (Van Valkenburgh et al., 1990). On the contrary, the presence of puma-like cats in Eurasia deserves further consideration regarding the origins of American pumas from a phylogenetic and biogeographic viewpoint. The puma-like cat P. pardoides is recorded from western Europe to central Asia from the MN16 until the MN17, and hereafter this taxon is not recorded (with the possible exception of the scarce remains from Pirro Nord) until above the base of the Jaramillo chron in Untermassfeld and several other sites. The chronology of P. pardoides in the Iberian Peninsula also ranges from the Late Pliocene to the latest Early Pleistocene, thus coinciding with the range of the species elsewhere in Eurasia. The disappearance of P. pardoides from the Eurasian fossil record occurs at the Early/Middle Pleistocene boundary, coinciding with the arrival of leopards into this continent, which became a common element from the late Middle to the Late Pleistocene (Palombo et al., 2008). This suggests that, if the Eurasian P. pardoides and the extant P. concolor are indeed closely related, the former must have dispersed across the Bering Strait during the Middle Pleistocene, before its first record in the American continent (Van Valkenburgh et al., 1990). Given the 400 kyr gap between the last European record of puma-like cats and their first American record, it may be hypothesized that pumas inhabited northern Asia during the early Middle Pleistocene, before dispersing into America. A revision of the Asian fossil material would be required in order to decipher whether puma-like remains have been incorrectly determined due to their similarities with leopards and snow leopards. Unfortunately, this issue is further complicated by the uncertainties surrounding the origin of the snow leopard, U. uncia. Its fossil record is very scarce, and only a few citations from the Late Pleistocene Altai Caves are probably correct (Hemmer, 1972). The recent assignment by Hemmer (2003) of a mandible from the Middle Pleistocene Aragó Cave to Uncia uncia was disputed by Testu (2006), who assigned it to Panthera sp. On the other hand, Olive (2006) noted the presence of derived features of U. uncia in the puma-like cranium QSV 136 from Saint-Vallier. The presence of these exclusive snow leopard characters in the Saint-Vallier cranium further implies that puma-like Eurasian cats might be also closely related to the former. Studies of molecular phylogeny are not conclusive to this regard. It has been recently concluded that U. uncia and P. leo may be sister taxa (Wei et al., 2008), but other analyses have alternatively concluded that the former is a stem member of the Panthera clade (Johnson et al., 2006), that it is a close relative of P. tigris (Linnaeus, 1758) (Jae-Heup et al., 2001), or that it is the sister taxon of P. pardus (Yu and Zhang, 2005). Most of these studies also support a close relationship between P. concolor and Acinonyx pardinensis with the exclusion of the snow leopard (Johnson et al., 2006), thus further complicating the phylogenetic interpretation of Eurasian puma-like cats that share morphological features with both extant pumas and snow leopards.


5. Conclusions 
The Iberian record of the enigmatic, Eurasian felid Puma pardoides includes in the localities of La Puebla de Valverde (MN17), Cueva Victoria (base of the Jaramillo subchron) and Vallparadís (below the Brunhes-Matuyama boundary). The Iberian specimens share many dentognathic features with those from Saint-Vallier (France), and further closely resemble the extant Puma concolor, even though the fossil specimens are clearly more robust both cranially and poscranially, and closer in size to the maximum figures of the extant species. Although the material described in this paper shares cranial and poscranial features with the snow leopard (Uncia uncia), it can be distinguished from the latter on the basis of significant dentognathic characters. Despite some recent claims on the phylogenetic significance of these similarities between the Old World puma-like cats and snow leopards, the lack of fossil remains from the latter preclude an accurate deciphering of their affinities. On the other hand, the puma-like fossil remains described in this paper significantly contribute to our understanding of the evolutionary history of the puma lineage. In particular, they confirm that Eurasian puma-like cats (Puma pardoides) are indeed closely related to American pumas (Puma concolor), further showing that Eurasian pumas are recorded from the Late Pliocene until the latest Early Pleistocene. Overall, from a paleobiogeographic viewpoint, this is consistent with the puma lineage having originated in Eurasia. Reply