Cite as:

Ghaffar, A., Akhtar, M., Khan, M.A., Babar, M.A., 2019. Comments on Percrocuta carnifex (Carnivora, Percrocutidae) based on new fossil material from the Nagri Formation (Middle Siwaliks) of Hasnot, Pakistan. Geologica Acta, 17.3, 1-9. DOI: 10.1344/GeologicaActa2019.17.3

INTRODUCTION

The Hasnot area, Pakistan, is famous for its fossil assemblages of very diverse mammalian fauna from the well exposed Chinji, Nagri, Dhok Pathan and Soan formations (Fig. 1), but the carnivores from the Siwalik Hills remain very poorly documented (Ghaffar and Akhtar, 2012; Ghaffar et al., 2011; Ghaffar, 2005; Pilgrim, 1932; Lydekker, 1884). The most important Middle Siwalik carnivore localities after the type localities of Nagri and Dhok Pathan formations are the localities from the Hasnot area (Wang et al., 2013; Ghaffar and Akhtar, 2012; Khan et al., 2009; Khan, 2007; Ghaffar, 2005; Barry et al., 2002, 1982; Behrensmeyer et al., 1995; Wills and Behrensmeyer, 1995; Barry and Flynn, 1989; Johnson et al., 1982; Cheema et al., 1977).

Different species of percrocutoid hyaenids, of late Middle Miocene (Chinji Formation) to Late Miocene (the Nagri and Dhok Pathan formations) age, have been reported from the Siwaliks of Pakistan (Ghaffar et al., 2011; Morales and Pickford, 2006; Ghaffar, 2005; Howell and Petter, 1985; Kurtén, 1957; Colbert, 1935; Matthew, 1929; Pilgrim, 1932, 1931, 1913; Lydekker, 1884). The described species were ascribed to either the Hyaena or Crocuta genera of Hyaenidae. Kretzoi (1938) erected the genus Percrocuta for some percrocutoid forms of the family Hyaenidae [hyaenids of relatively small size and with a reduced protocone in the upper carnassial (P4)], but he was largely ignored, and several of these forms were subsequently ascribed to various genera, usually to Crocuta. In a major study of these forms, Kurtén (1957) reinstated the subgenus Percrocuta. Posteriorly, Schmidt- Kittler (1976) and Guanfang and Schmidt-Kittler (1983) suggested the distinction of percrocutids from the hyaenids based on the deciduous dentition. Werdelin and Solounias (1991) removed them from the family Hyaenidae, and placed them in the separate family Percrocutidae, which includes the genera Percrocuta and Dinocrocuta (Morales and Pickford, 2006; Werdelin and Kurtén, 1999; Howell and Petter, 1985). According to Kurtén (1957), Percrocuta comprises the dominant hyenas of the Pliocene. Taxonomic characteristics of species of this group from Asia, Europe and Africa have been described in detail (Kurtén 1957; Guanfang and Schmidt-Kittler, 1983; Howell and Petter, 1985). The main aim of this paper is to present the taxonomic study of a new specimen described here and to comment on the stratigraphy of the specimens from the Siwalik continental deposits described by earlier authors (Ghaffar et al., 2011; Pilgrim, 1932).

GEOLOGICAL SETTING

The specimen PUPC 2016/16A, was collected in the fossiliferous site of the Hasnot village (32.82855°; 73.31510°), located about 54km west of the Jhelum city in the Potwar Plateau of northern Pakistan (Fig. 1). In this area, extensive Neogene continental sedimentary rocks are well exposed. The region of Hasnot exposes the most complete sequence of the Siwalik Group (Kamlial, Chinji, Nagri, Dhok Pathan and Soan formations) and has yielded diverse fossil assemblage, mostly in the Dhok Pathan Formation. Fossil sites around Hasnot village are located in fine-grained fossil bearing floodplain deposits characteristic of a fluvial depositional environment (Barry et al., 2002, 1982; Barry and Flynn, 1989). The Chinji and Dhok Pathan formations are mud dominated whereas the Nagri and Soan formations are sand dominated (Wang et al., 2013; Willis and Behrensmeyer, 1995; Behrensmeyer et al., 1995). In the study area, the Nagri Formation consists of sandstone with subordinate clay and conglomerate intercalations. The sandstone is greenish grey, medium to coarse grained, moderately to poorly cemented, and cross-bedded, while the clay is sandy, reddish grey and pale orange; the proportion of the different deposits varies from section to section. The conglomerate beds vary in thickness and composition. The conglomerate beds in this area consists of pebbles of igneous rocks and Eocene limestone, similar to the conglomerates from the type section of the Nagri Formation. This formation has yielded fairly rich assemblages of vertebrate remains i.e.Trilophodon, Pentalophodon, Dinotherium, Stegolophodon, Tetraconodon, Gaindatherium browni, Aceratherium lydekkeri, Chilotherium intermedium, Macrotherium salinum, Giraffokeryx punjabiensis, Dorcabune nagrii, Dorcatherium minus, Hemimeryx, Listriodon pentapotamiae, Palaeochoerus perimensis, Meganteron, Amphicyon palaeindicus, Lycyaena, Orycteropus browni, Crocuta carnifex and Eotragus spp. (Shah, 2009; Khan, 2007; Ghaffar, 2005; Barry et al., 2002; Pilbeam et al., 1977; Colbert, 1935; Pilgrim, 1932, 1913, 1910; Matthew, 1929; Lydekker, 1884).

MATERIAL

The specimen described in this paper (PUPC 2016/16A) belongs to the Abu-Bakr Fossil Display and Research Centre, University of the Punjab (Lahore, Pakistan) and was collected by research associate, Mr. Muhammad Akhtar, of the Zoology Department during the winter season of 1984. The stratigraphic information of the fossil site, found with the specimen, revealed that it was collected from the Nagri Formation of Hasnot area. This locality lies across the Bunnah River, 2km SE of Hasnot village. For the comparative analysis, we used the material from the Siwaliks (PUPC 2009/1) described by Ghaffar et al. (2011), and the measurements of the specimens reported by Pilgrim (1932) and Howell and Petter (1985), which were based on the photographs/plates included in the respective papers. The lower dentition (GSI D 169–172; AMNH 19405 and CU-PUPC 2009/1) and two maxillary fragments (GSI D 168 and 173) described by Pilgrim (1932) were considered but not included in Table 1, as the material under study belongs only to the lower dentition.

Abbreviations. Organizations: AMNH: American Museum of Natural History New York; BMNH: British Museum of Natural History, London; CU-PUPC: COMSATS University-Punjab University Paleontological Collection; GSI: Geological Survey of India, Calcutta; IVPP: Institute of Vertebrate Paleontology and Paleoanthropology, Beijing; MNHN: Museum National d’Histoire Naturelle, Institute de paléontologie, Paris; NMB: National Museum, Belgrade; PIN: Paleontological Institute, Academy of Sciences, Moscow, USSR; PUPC: Punjab University Paleontological Collection.

Palaeontology. L: length; Ma: million years ago; d2: second lower deciduous molar; d3: third lower deciduous molar; d4: fourth lower deciduous molar; m1: first lower molar; m2: second lower molar; M2: second upper molar; mm: millimeters; p1: first lower premolar; p2: second lower premolar; p3: third lower premolar; p4: fourth lower premolar; P3: third upper premolar; P4: fourth upper premolar; W: width.

Previously described specimens from the Siwaliks with comments on the stratigraphy

To this date, the following specimens of Percrocut carnifex (pilgrim, 1913) had been described (Ghaffar et al., 2011; Colbert, 1935; Pilgrim, 1932, 1913) from the Siwalik continental deposits:

i) GSI D 164; right m1, collected from Dhok Pathan Formation, Hasnot (Jhelum district).

ii) GSI D 168; left P4, collected from the Chinji Formation, Chinji.

iii) GSI D 169; a left mandibular ramus with the base of canine broken and p2-3, collected from the Chinji Formation, Chinji.

iv) GSI D 170; a left mandibular ramus with alveolus of canine and (p2-3, collected from the Chinji Formation, Chinji.

v) GSI D 171; a left mandibular ramus with p3-4, collected from the Chinji Formation, Chinji.

vi) GSI D 172 (holotype); a right mandibular ramus with d2-4, canine, p2-4 and molar (m1), collected from the Chinji Formation, Chinji.

vii) GSI D 173; right maxilla with canine and P2-3 collected from the Chinji Formation, Chinji.

viii) AMNH 19405; a left mandibular ramus with p4 and m1, collected from the Chinji Formation, Chinji (four miles northeast of Chinji Rest House).

ix) CU-PUPC 2009/01; left mandibular ramus with p3 and m1 collected from the Nagri Formation, near the village of Nagri Sethi.

Among the material described by Pilgrim 1932, only the specimen GSI D 164 is said to come from the Dhok Pathan Formation of Hasnot, but there is not an exact record of the fossil site. Moreover, the smaller length of the tooth of this specimen compared with the specimen described here suggests that this specimen is not as young as the Dhok Pathan Formation. Although the exact stratigraphic position of the rest of the listed specimens is not known, the lithological characteristics and stratigraphic context of their sites suggest that none of the specimens come from the Dhok Pathan Formation, then this species was probably restricted to the Chinji and Nagri formations.

The type specimen of P. carnifex, GSI D 172, and GSI D 173, were collected by Pilgrim (1932, 1913) from the top of the Chinji Formation south of the Nagri village. The specimens GSI D 168, 169, 170, and 171 were also collected by Pilgrim (1932, 1913) from the Chinji Formation. The type locality of this species is situated east of Chinji and south of the Nagri village. Colbert (1935) described a specimen (AMNH 19405) assigned to this species from the lower Chinji beds, four miles northeast of the Chijni Rest House. More recently, Ghaffar et al. (2011) described another specimen (CU-PUPC 2009/01) from the type section of the Nagri Formation. Among the material described by Pilgrim 1932, only specimen GSI D 164 is believed to come from the Dhok Pathan Formation of Hasnot, without an exact record of the location of the fossil site, as it had been collected by some native person of this vicinity.

According to the stratigraphic context and morphometric analysis of the already described specimens (Howell and Petter, 1985; Kurtén, 1957), we believe that all these were collected from the Chinji-Nagri formations, as the specimen described in this study came from Nagri Formation, near Hasnot village. Similarly, the small tooth length of the specimen GSI D 164 as compared to the specimen described here confirms that this specimen is not as young geologically as the Dhok Pathan Formation.

SYSTEMATIC PALAEONTOLOGY

Order: Carnivora Bowdich, 1821

Family: Percrocutidae Werdelin and Solounias, 1991

GENUS Percrocuta Kretzoi, 1938

Type species: Percrocuta carnifex (Pilgrim, 1913)

Holotype. GSI D 172, right mandibular ramus of a juvenile individual from Chinji Formation with d2-4, canine and p2-m1.

Diagnosis. Percrocutid of relatively small size. Last molars (M2/m2) lost. The m1 is lacking a metaconid or presents a residual–metaconid; tendency toward shortening of the talonid and elongation of the trigonid. P3 with or without an internal root; P4 with a reduced protocone, situated more or less posteriorly to the anterior margin of the parastyle. Specialization of the dentition distinguished by hypertrophy of the anterior premolars; p2 and p3 are short (relative to p4 and m1) and broad with high robusticity indices (Howell and Petter, 1985).

Species: Percrocuta carnifex (Pilgrim, 1913)

Material. PUPC 2016/16A is a fragmentary right mandible including p2 and m1 with the crown of p3 broken (Fig. 2). (Error 1: La referencia: Fig. 2 está ligada a un elemento que ya no existe)

Description. The preserved length of the mandibular ramus is 132.0mm, whereas the maximum breadth of this ramus is 19.0mm. The depth of the ramus below p2 and m1 is 36.0mm and 44.0mm, respectively. It presents an excellent state of preservation and the teeth are at medium wear. The main cusp of p2 is high with a rudimentary posterior cusp. The p3 is missing but its base is preserved, which gives the rough estimates about the tooth structure and size: its antero-posterior and transverse dimensions indicate the hypertrophy of this tooth (Table 1). Similarly, the main cusp of p4 is high, with well-developed anterior and posterior cusps of equal size. For m1, the paraconid is somewhat broader than the protoconid, which, however, is somehow taller and narrower than the former. A small cingulum is also present at the antero-buccal side of paraconid. A very small talonid is much reduced as compared to the trigonid. Both p4 and m1 show a finely wrinkled enamel. One prominent mental foramien is present below the midpoint of p2 about halfway down the depth of the jaw.

DISCUSSION

The mandibular ramus described here is missing its anterior region including the canine, but canine alveolus indicates a large canine was present. Similarly, the mandibular ramus is very smooth anterior to p2, giving the impression of a diastema and of the absence of p1, a characteristic also noted by Pilgrim (1932) in the type specimen of P. carnifex. The p2, with a prominent main cusp and a rudimentary posterior accessory cusp, is similar to the p2 of the type specimen as well as to GSI D 170. The slight difference noted for the p2 here described is that in the type specimen as well as in GSI D 170, it is straight whereas in the specimen described here it is tilted backward. The upper crown of p3 is missing, but the basal outline including the anterior and posterior accessory cusps is preserved, indicating that it is a larger tooth than p2 and equal in size to p4. Also, its anterior and posterior accessory cusps are very similar to the type material and other specimens (i.e. GSI D 169, 170), but the anterior and posterior accessory cusps are more prominent if compared to specimen CU-PUPC 2009/1. In p4, the anterior and posterior cusps are prominent and similar to type material, GSI D 171, AMNH 19405 and CU-PUPC 2009/1. The posterior portion of the p4 (posterior cusp) here described is overlapping with the anterior portion (paraconid) of m1 and this overlapping is also evident in AMNH 19405 but not observed in type material and GSI D 171. In the m1 described here, the paraconid, protoconid and unicuspid talonid are well preserved and similar to those in the type specimen and other specimens, such as GSI D 164, AMNH 19405 and CU-PUPC 2009/1. Moreover, in the m1 here described, the paraconid is broader than the protoconid whereas the protoconid is taller than the paraconid. The paraconid is broader as compared to the protoconid in all the specimens but in the type material, as well as in CU- PUPC 2009/1, these conids are almost equal in height. A protoconid taller than the paraconid, very similar to the situation seen in the m1 here described, can be observed in specimens GSI D 164 and AMNH 19405. In the type material and in GSI D 169, 171, the main cusps in p3-4 are tapering anteriorly, whereas they appear to be somehow blunt in the p3-4 of the specimen here described, of CU- PUPC 2009/1 and AMNH 19405, a difference that is due to the different stage of wear in these specimens. The above mentioned characteristics in comparison with the type material (GSI D 172) as well as all other specimens described from the Siwaliks allow us to assign this specimen to P. carnifex.

Morphometric analysis

According to the measurements (Table 1), the p2 described here is longer than the p2 in specimens GSI D 169, 170, 172, but narrower than GSI D 170. Similarly, the p3 here described is longer than the p3 in GSI D 169, 170, 171, 172, and shorter than CU-PUPC 2009/01, but is wider than GSI D 171, CU-PUPC 2009/01, and narrower than GSI D 169, 170. Moreover, the p4 described here is longer and wider than the p4 in GSI D 164, 172, AMNH 19405, CU- PUPC 2009/01. The length of m1 described here is bigger than the m1 in GSI D 164, 172, AMNH 19405, and smaller than CU-PUPC 2009/01, but narrower than GSI D 164, 172, AMNH 19405, CU-PUPC 2009/01 (Fig. 3). Similarly, the p2 described here is longer than the p2 in Percrocuta abessalomi (Gabunia, 1973), Percrocuta tobieni, Percrocuta hobeiensis and Percrocuta miocenica (Ciric, 1960), shorter than in Percrocuta tungurensis (Colbert, 1939), Percrocuta grandis (Kurtén, 1957), Percrocuta gigantea (Schlosser, 1903) and Percrocuta sp. from Al Jadidah, wider than in P. abessalomi, P. tobieni, P. hobeiensis, and equal to the ones of P. miocenica, and narrower than in P. tungurensis, P. gigantea and P. grandis. The p3 described here is longer than the p3 in P. abessalomi, P. tobieni, P. hobeiensis, P. miocenica, P. tungurensis, shorter than in P. gigantea, while broader than in P. abessalomi, P. tobieni, P. hobeiensis, P. miocenica and Percrocuta sp. from Al Jadidah, and narrower than P. tungurensis and P. gigantea. The p4 described here is longer than the p4 in P. abessalomi, P. tobieni, P. hobeiensis, P. miocenica, equal to the ones seen in P. tungurensis, and shorter than in P. gigantea and in P. grandis, while being wider than in P. abessalomi, P. tobieni, P. hobeiensis, P. miocenica, and narrower than in P. tungurensis, P. gigantea and P. grandis. The m1 described in this paper is longer than the m1 in P. abessalomi, P. tobieni, P. hobeiensis, P. miocenica and Percrocuta sp. from Al Jadidah, while being shorter than in P. tungurensis and P. grandis, and wider than in P. abessalomi, P. tobieni, and Percrocuta sp. from Al Jadidah, and narrower than in P. miocenica and P. tungurensis (Fig. 3).

Morales and Pickford (2006) argued that percrocutids from the Late Miocene are larger than Middle Miocene species. Similarly, a gradual increase in size was observed in Eurasia from the small species P. abessalomi, P. tungurensis, P. miocenica to large species in the Late Miocene, such as P. gigantea and P. grandis. This gradual increase in size is also evident within the single species as the specimens recovered from Chinji Formation (GSI D 169, 170, 171, 172, AMNH 19405) have smaller lengths than those from the Nagri Formation (CU- PUPC 2009/01 and the specimen described here). Similarly, on the basis of tooth size, P. carnifex is smaller than P. grandis. On the basis of above statement, we can argue that specimen GSI D 164 may also belong to either the Chinji Formation or Nagri Formation rather than the Dhok Pathan Formation and more probably to the Chinji Formation, because the length and width of m1 fits well with the specimens described from this formation. If these observations are correct, they also indicate that no fossil material of P. carnifex has been recovered from the Dhok Pathan Formation yet.

Historical review and Stratigraphic analysis

After Pilgrim (1932), hyaenids of the Middle Siwaliks were critically studied by Kurtén (1957), by opting Percrocuta as a subgenus of Crocuta. On the basis of size differences and protocone structure in the upper premolar (P4), he recognized 5-6 species of percrocutids from the Siwalik Hills of the Indian subcontinent. Moreover, he argued that the metastyle blade of P4 in Percrocuta is longer than in Hyaena but shorter than in Crocuta. In P. carnifex, the trigonid of m1 is somewhat long, with a short talonid. As a result, unicuspid talonids can only be seen in this species as compared to other species of this genus. He also noted that this species appeared during the Early Pliocene, but more recently, Barry et al. (2002) established that the Chinji Formation belongs to late Middle Miocene (14.2–11.2Ma) and the Nagri Formation to the Late Miocene (11.2–9.5Ma).

Percrocutids appeared in the upper Middle Miocene, or Astaracian, in Eurasia and persisted for at least 3 million years (Howell and Petter, 1985), while in the Siwalik continental deposits they persisted longer than in Eurasia, as one species P. grandis (Kurtén, 1957) is described from the Dhok Pathan Formation. Moreover, during the Vallesian, Adcrocuta, Adcrocuta eximia (Pilgrim, 1932) was widely spread and it limited the expansion of percrocutids in Eurasia. From the Siwalik continental deposits, fossils of A. eximia were recovered from the DhokPathan Formation, and it possibly limited the distribution of percrocutids as the latter are mostly recovered and described from thr Chinji and Nagri formations. On the other hand, no fossil record of A. eximia is known to date from the Chinji or Nagri formations of the Siwaliks.

As mentioned earlier, a detailed description of different species of Percrocuta was made by Kurtén (1957) and Howell and Petter (1985). This genus appeared at the base of the Astaracian land mammal age, but the root of this group is still unclear, that is, the ancestors of P. abessalomi, P. tobieni and P. miocenica are unknown (Howell and Petter, 1985). However, these African species are considered more primitive than the Eurasian and Siwalik species. Some features are more specialized in P. miocenica than in P. abessalomi found in southeast Europe, Anatolia and eastern China, moreover, P. miocenica had a vast distribution with limited duration, being restricted to an earlier Astaracian age (MN zone 6), while P. carnifex, had a limited distribution and a duration longer than P. miocenica. A number of specimens of P. carnifex from the Chinji and Nagri formations of Siwaliks have been described. Howell and Petter (1985) suggested a close relationship between Percrocuta sp. from Al Jadidah and P. carnifex from Siwaliks by faunal exchange between the northern part of the Indian subcontinent and western Asia during the Late Astaracian. In western Asia, P. carnifex may have replaced P. miocenica and, according to Howell and Petter (1985), P. tungurensis was restricted to Mongolia, but it is known from Çandir, Turkey (Mayda et al., 2015; Schmidt-Kittler, 1976). Thenius (1966) and Soria (1980) argued that P. tungurensis derived from P. carnifex, and the stratigraphic analysis of the Tung Gur Formation of Mongolia and of the Chinji Formation supports this idea.

Phylogenetic relationships

Although p3 is not present in the specimen described here, its base is preserved and can be compared with Percrocuta sp. from the Hofuf Formation, Al Jadidah, Saudi Arabia (Middle Astaracian). This comparison shows that the basal outline of p3 is similar in both species. On the basis of material described here (i.e. lower dentition) and material from the Siwaliks described by previous authors, it is impossible to draw any conclusion regarding the ancestry of P. carnifex, but we can draw the following conclusions:

i) the hypertrophy of p3 in Percrocuta sp. from Al Jadidah, and in P. carnifex (based on the measurements of its base) from Siwaliks suggests a relationship between these two species, but Percrocuta sp. has an older stratigraphic range.

the hypertrophy of p3 and small size of m1 in the material described here show that P. carnifex is closer to P. tobieni and P. miocenica than to P. abessalomi and P. tobieni, although the morphological differences with P. abessalomi are slight (Howell and Petter, 1985). Similarly, the presence of a median internal root in P3 in Percrocuta sp. from Al Jadidah, places this species in the lineage of either P. miocenica or P. carnifex or in a common lineage for these two species. It is worth noticing here that P. miocenica is older than Percrocuta sp. and younger than P. carnifex. The median internal root of P3 is absent in P. abessalomi a difference between this species and P. carnifex. Due to that P. miocenica and P. hebeiensis, have very similar mandibular material, these two species can be tentatively synonymized, but more material is needed to confirm it, particularly upper dentitions of P. hebeiensis. In general P. abessalomi show more primitive characters than the other species, it has an older stratigraphic range and a smaller size. These characters suggest that it is a primitive species; however, they do not denote any relation to other percrocutid species, particularly to P. carnifex. On the other hand, P. carnifex shares some characters with P. miocenica and P. tobieni. The relationship between all mentioned species is obscure. Moreover, the Al Jadidah specimen has some common characters with P. carnifex, P. tobieni and P. miocenica.

Soria (1980) synonymized P. abessalomi, P. miocenica and P. tobieni with P. carnifex. She suggested a new name for all these species, P. pilgrimi, and proposed two subspecies P. carnifex abessalomi (i.e. to stand for P. abessalomi and P. tobieni) and P. carnifex carnifex (i.e. to stand for P. miocenica and P. carnifex). This distinction was based on the robustness indices of p2 and p3, which are lower in P. carnifex abessalomi when compared to P. carnifex carnifex. According to Soria, the former subspecies is more primitive, and the latter derived from it, but the proposition of Soria was not followed, as it did not include the robustness indices of p4 and m1. In our opinion, synonymizing different species can only be justified if there is a direct relationship between them, and to synonymize the above mentioned species, more studies on their linkage have to be done.

CONCLUSION

Dentary material of Percrocuta carnifex from the Nagri Formation of Siwaliks, Pakistan, is described. The morphology and morphometric analysis of all specimens from Siwaliks suggests that, until now, there is no record of this species from the Dhok Pathan Formation or from any equivalents of this formation in the Siwalik Hills or outside the region. This species is probably restricted to the Chinji and Nagri formations. The dental morphological similarities between species from Asia, Africa and Europe, suggest that there was a certain amount of gene flow through the Eurasia and Africa continents. The discovery of new species of older stratigraphic range (Kamlial Formation) might resolve the issue of the ancestry of P. carnifex or provide phylogenetic links between the species of this genus from different continents.

Acknowledgements

The authors wish to thank Lars Werdelin for the preliminary identification of the new material and for kindly providing literature for this manuscript. The first author is also grateful to Raja M. Ibrahim (deceased) and his team (COMSATS Library Information Services) for their efforts to provide the necessary literature for this manuscript. We greatly acknowledge the efforts of all the reviewers for their critical and valuable suggestions that helped to improve this manuscript. This research was supported by Higher Education Commission, Pakistan (grant no. 20-2234/R and D/11) to Abdul Ghaffar under the National Research Program for Universities (NRPU).

References

Barry, J.C., Flynn, L.J., 1989. Key biostratigraphic events in the Siwalik sequence. In: Lindsay, E.H., Fahlbusch, V., Mein, P. (eds.). European Neogene Mammal Chronology, NATO ASI Series. Life Sciences, 180, 557-571. DOI: 10.1007/978-1- 4899-2513-8_33

Barry, J.C., Morgan, M.E., Flynn, L.J., Pilbeam, D., Behrensmeyer, A.K., Raza, S.M., Khan, I.A., Badgley, C., Hicks, J., Kelley, J., 2002. Faunal and environmental change in the late Miocene Siwaliks of northern Pakistan. Paleobiology, 28(2), 1-71.

Barry, J.C., Lindsay, E.H., Jacobs, L.L., 1982. A biostratigraphic zonation of the Middle and Upper Siwaliks of the Potwar Plateau of northern Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology, 37(1), 95-130.

Behrensmeyer, A.K., Wills, B.J., Quade, J., 1995. Floodplains and paleosols of Pakistan Neogene and Wyoming Paleogene deposits: a comparative study. Palaeogeography, Palaeoclimatology, Palaeoecology, 115(1-4), 37-60.

Cheema, M.R., Raza, S.M., Ahmad, H., 1977. Cainozoic. In: Shah, S.M.I. (ed.). Stratigraphy of Pakistan. Geological Survey of Pakistan Memoirs, 12, 56-98.

Ciriċ, A., 1960. Die Chios-Fauna von Prebreza (Serbien). Bulletin de l’Institut de Recherches Géologique et Géophysique de Belgrade, A 18, 109-131.

Colbert, E.H., 1939. Carnivora of the Tung Gur Formation of Mongolia. New York, Bulletin of the American Museum of Natural History, 76(2), 47-81.

Colbert, E.H., 1935. Siwalik mammals in the American Museum of Natural History. Transactions of the American Philosophical Society, Lancaster Press, INC., Lancaster, PA., New Series, 26, i-x, 1-401.

Gabunia, L., 1973. Fossil vertebrates of the fauna of Bjelometschskaya (in Russian). Akademii Nauk, Georgian Soviet Socialist Republics Tiflis, 138pp.

Ghaffar, A., 2005. Studies on equids, cervids and Carnivora from the Siwalik Hills of Pakistan. PhD Thesis. Lahore (Pakistan), University of the Punjab, 389pp.

Ghaffar, A., Akhtar, M., 2012. New fossil record of Hyaenictitherium pilgrimi (Carnivora: Hyaenidae) from Dhok Pathan Formation of Hasnot, Pakistan. Swiss Journal of Paleontology, 131(2), 275-281.

Ghaffar, A., Akhtar, M., Butt, M.J., Khan, M.A., Ikram, T., 2011. Late Miocene Hyaenids from the Middle Siwaliks of Pakistan. Pakistan Journal of Zoology, 43(5), 855-862.

Guanfang, C., Schmidt Kittler, N., 1983. The deciduous dentition of Percrocuta Kretzoi and the diphyletic origin of hyaenas (Carnivora, Mammalia). Paläontologische Zeitschrift, 57(1- 2), 159-169.

Howell, F.C., Petter, G., 1985. Comparative observations on some Middle and Upper Miocene hyaenids. Genera: Percrocuta Kretzoi, Allohyaena Kretzoi, Adcrocuta Kretzoi (Mammalia Carnivora, Hyaenidae). Geobios, 18(4), 419-476.

Johnson, N.M., Opdyke, N.D., Johnson, G.D., Lindsay, E.H., Tahirkheli, R.A.K., 1982. Magnetic polarity stratigraphy and ages of Siwalik group rocks of the Potwar Plateau, Pakistan. Palaeogeography, Palaeoclimatology, Palaeoecology, 37(1), 17-42.

Khan, M.A., 2007. Taxonomic studies on fossil remains of ruminants from Tertiary Hills of Hasnot, Pakistan. PhD Thesis. Lahore (Pakistan), University of the Punjab, 292pp.

Khan, M.A., Iliopoulos, G., Akhtar, M., 2009. Boselaphines (Artiodactyla, Ruminantia, Bovidae) from the Middle Siwaliks of Hasnot, Pakistan. Geobios, 42(6), 739-753.

Kretzoi, M., 1938. Die Raubtiere von Gombaszog nebst einer Ubersicht der Gesamtfauna. Annales Musei Nationalis Hungarici, 31, 89-157.

Kurtén, B., 1957. Percrocuta Kretzoi (Mammalia, Carnivora), a group of Neogene hyaenas. Acta Zoologica Cracoviensia, 2, 375-404.

Lydekker, R., 1884. Indian tertiary and post-tertiary vertebrate. Vol. 2. Part 6. Siwalik and Narbada Carnivora. Memoirs of the Geological Survey of India, Palaeontologia Indica, 10, 178-351.

Matthew, W.D., 1929. Critical observations upon Siwalik Mammals. Bulletin of the American Museum of Natural History, 56, 437-560.

Mayda, S., Koufos, G.D., Kaya, T., Gul, A., 2015. New carnivore material from the Middle Miocene of Turkey. Implications on biochronology and palaeoecology. Geobios, 48(1), 9-23.

Morales, J., Pickford, M., 2006. A large Percrocutid Carnivore from the Late Miocene (ca. 10–9 Ma) of Nakali, Kenya. Annales de Paléontologie, 92(4), 359-366.

Pilbeam, D., Barry, J., Meyer, G.E., Shah, S.M.I., Pickford, M.H.L., Bishop, W.W., Thomas, H., Jacobs, L.L., 1977. Geology and palaeontology of Neogene strata of Pakistan. Nature, 270(5639), 684-689.

Pilgrim, G.E., 1932. The fossil Carnivora of India. Memoirs of the Geological Survey of India, Palaeontologia Indica, 18, 1-232.

Pilgrim, G.E., 1931. Catalogue of the Pontian Carnivora of Europe in the Department of Geology. London, British Museum (Natural History), 174pp.

Pilgrim, G.E., 1913. Correlation of the Siwaliks with Mammal Horizons of Europe. Records of Geological Survey of India, 43, 264-326.

Pilgrim, G.E., 1910. Notices of new mammalian genera and species from the Territories of India. Records of the Geological Survey of India, 40, 63-71.

Schlosser, M., 1903. Die fossilen Säugetiere Chinas, nebst einer Odontographie der recenten Antilopen. Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch- Naturwissenschaftliche Klasse, 22, 1-221.

Schmidt-Kittler, N., 1976. Raubtiere aus dem Jüngtertiӓr Kleinasiens. Palaeontographica A, 155, 1-131.

Shah, S.M.I., 2009. Stratigraphy of Pakistan. Geological Survey of Pakistan Memoirs, 22, 1-381.

Soria, D., 1980. “Percrocuta y Adcrocuta” (Hyaenidae, Mammalia) en el Mioceno superior del área de Teruel. Madrid, Estudios Geológicos, 36(1), 143-161.

Thenius, E., 1966. Zur Stammesgeschichte der Hyänen (Carnivora, Mammalia). Zeitschrift, für Sӓugetierkunde, 31, 292-300.

Wang, X., Flynn, L.J., Fortelius, M., 2013. Introduction: Toward a Continental Asian Biostratigraphic and Geochronologic Framework. In: Wang, X., Flynn, L.J., Fortelius, M. (eds.). Fossil Mammals of Asia: Neogene biostratigraphy and chronology. New York, Columbia University Press, 1-26. Available at: https://dash.harvard.edu/handle/1/27867246

Werdelin, L., Kurtén, B., 1999. Allohyaena (Mammalia: Carnivora): giant hyaenid from the Late Miocene of Hungary. Zoological Journal of the Linnean Society, 126(3), 319-334.

Werdelin, L., Solounias, N., 1991. The Hyaenidae: taxonomy, systematics and evolution. Fossils and Strata, 30, 1-104.

Wills, B.J., Behrensmeyer, A.K., 1995. Fluvial systems in the Siwalik Neogene and Wyoming Paleogene. Palaeogeography, Palaeoclimatology, Palaeoecology, 114(1-4), 13-35.

Author notes

aghaffar@cuvas.edu.pk

Alternative link

http://dx.doi.org/10.1344/GeologicaActa2019.17.3 (pdf)

http://revistes.ub.edu/index.php/GEOACTA/article/view/GeologicaActa2019.17.3/29036 (html)