Chaeropus yirratji Travouillon 2019
- Dataset
- Hidden in plain sight: reassessment of the pig-footed bandicoot, Chaeropus ecaudatus (Peramelemorphia, Chaeropodidae), with a description of a new species from central australia, and use of the fossil record to trace its past distribution
- Rank
- SPECIES
- Published in
- Travouillon, Kenny J., Simões, Bruno F., Miguez, Roberto Portela, Brace, Selina, Brewer, Philippa, Stemmer, David, Price, Gilbert J., Cramb, Jonathan, Louys, Julien (2019): Hidden in plain sight: reassessment of the pig-footed bandicoot, Chaeropus ecaudatus (Peramelemorphia, Chaeropodidae), with a description of a new species from central australia, and use of the fossil record to trace its past distribution. Zootaxa 4566 (1): 1-69, DOI: 10.11646/zootaxa.4566.1.1
Classification
- kingdom
- Animalia
- phylum
- Chordata
- class
- Mammalia
- order
- Peramelemorphia
- family
- Chaeropodidae
- genus
- Chaeropus
- species
- Chaeropus yirratji
description
(Figs. 8 – 11) urn: lsid: zoobank. org: act: C 2806112 - 0347 - 4 E 64 - B 333 - C 287 D 36 EE 62 E
description
Description. The description is that of the holotype, with reference to the paratypes to illustrate the variation in morphology within the species. Pelage is chestnut on the dorsal side, light greyish brown on the lateral and ventral sides, and limbs (also in NMV C 470). The ventral side is cream or white in colour in MNHN ZM MO- 1853 - 824, SAMA M 1618, NMV C 469, C 471, C 5857, C 5858, C 5860, and C 5861. The pelage in SAMA M 2425, M 2426 and M 3971 is very different. It is golden dorsally, and beige laterally and ventrally. We do not think that this is a result of fading, as fading would have not occurred in the same way in dry (SAMA M 2425 and M 2426) and wet (SAMA M 3971) specimens. Instead, it is more likely that this taxon exhibits two pelage forms, as in many mammals in Australia (e. g., Wallabia bicolor, Hemibelideus lemuroides, Trichosurus vulpecula, Hipposideros ater). We extracted the skull of SAMA M 3971 to make sure that the skull morphology was consistent with the dark form, which it was. The tail is lightly furred laterally, with a dark crest of fur dorsally becoming paler posteriorly, and a shorter light crest of fur ventrally. Tail is on average longer than in Chaeropus ecaudatus (> 120 mm in adults), though it is unclear how much tail breakage has occurred in some specimens Hind feet are longer than in C. ecaudatus,> 70 mm in adults. The morphology of the feet and head does not differ from C. ecaudatus otherwise. Pouch young morphology is represented by SAMA M 3997 and NMV C 5859. In SAMA M 3997, a portion of the pouch nipples have been cut away from the mother, showing three active nipples. Two of the pouch young are still attached, and the third fell off. The pouch young are most likely only a few days old based on the external developmental stage. Their heads are elongated as in all bandicoots. The fore and hind paws are well-developed with three large toes, unlike in the adult. NMV C 5859 is a female and older than the pouch young. The snout is shorter on this specimen than on SAMA M 3997, but the fore and hind paws have the adult morphology of two large toes on the forepaw (the third toe is reduced to a nob), and a large toe on the hind paw (the other toes are present but highly reduced). The skull, in dorsal view, is very similar to that of Chaeropus ecaudatus. The nasals are narrower posteriorly than in C. ecaudatus. The maxillary-frontal suture is crooked as in C. ecaudatus, but more curved. The lacrimal is more massive than in C. ecaudatus and is longer laterally. In lateral view, the incisivomaxillary canal is smaller in size and more posteriorly positioned relative to C. ecaudatus, within the entrance of the infraorbital foramen (except in NHMUK ZD 1857.10.24.19, where it is more anteriorly positioned). The ventral margin of the premaxilla is shorter, but taller, than in C. ecaudatus. The bullae are more evenly rounded ventrally, compared to C. ecaudatus. In ventral view, the lateral accessory palatal fenestrae are shorter than in C. ecaudatus, not extending anteriorly past the anterior tip of P 1 (except in MNHN ZM AC- 1880 - 422, on the right side only, and NHMUK ZD 1857.10.24.19, left side only), and narrower anteriorly than posteriorly (it is similar in width along its length in C. ecaudatus). The medial accessory palatal fenestrae are poorly developed, representing only a few small irregularly shaped fenestrae. The maxillary fenestrae are absent. The maxillopalatine fenestrae are more posteriorly positioned; anteriorly, they are level with the anterior of M 1 (level with the middle of P 3 in C. ecaudatus), and posteriorly, level with the posterior of M 2 (level with the middle of M 2 in C. ecaudatus). The palatine fenestrae are more regular (more rounded) in shape than in C. ecaudatus. The presphenoid and the basisphenoid are in contact (not fully contacting in C. ecaudatus). The carotid foramen is oval, with a distinct ventral wall of basisphenoid, so that the foramen opens laterally, as in all other peramelemorphians (except C. ecaudatus in which it opens ventrally). The secondary foramen ovale is separated from the primary foramen ovale by a longer portion of alisphenoid, resulting in a more anterolateral position relative to C. ecaudatus. The promontorium of the petrosal is straighter and more laterally directed than in C. ecaudatus (where it is more curved and more ventrally directed) and transitioned more smoothly with the basioccipital. The dentary does not differ from that of C. e. ecaudatus, except in having a more anteriorly positioned anterior mental foramen; anterior to p 1 instead of level with the midpoint of p 1 (also in C. e. occidentalis). The dentition is particularly worn on the holotype, and so SAMA M 1618 and M 3971 are described here. The I 1 – 5, C 1, and P 1 – 3 do not differ in morphology to that of C. ecaudatus. On the M 1, the paracone and StA only connect as a result of wear (there is no crest connecting these two cusps in unworn teeth). StB is more massive than in C. ecaudatus, extending more anterolingually. A large StD 1 is present anterior to StD, and connected to the premetacrista. The metaconule is larger and the postmetaconulecrista ends posterior to the metacone (lingual to metacone in C. ecaudatus). The M 2 and M 3 only differ from that of C. ecaudatus in having a larger metaconule with a postmetaconulecrista ending posterior to the metacone, making the tooth shape more square (more triangular in C. ecaudatus). The M 4 is similar to that of C. ecaudatus but StB and the metacone are reduced in size, shortening the length of the tooth. The i 1 – 3, c 1, and p 1 – 3 do not differ in morphology to that of C. ecaudatus. The m 1 trigonid is longer than in C. ecaudatus, and the paracristid is not continuous, and does not connect to the protoconid in unworn teeth (similar condition seen in Perameles pallescens). The m 2 – 4 are indistinguishable to those of C. ecaudatus.
diagnosis
Diagnosis. Chaeropus yirratji differs from C. ecaudatus in having longer hindfeet and tail; lacking maxillary fenestrae; lacking distinct medial accessory palatal fenestrae; having a more developed metaconule on M 1 – 3, making the molars more rectangular in shape; carotid foramen opens laterally; StD 1 present on M 1; metacone of M 4 is reduced; and the paracristid on m 1 is not continuous.
distribution
Distribution. Arid zone of the Flinders Ranges (South Australia), central Australia (Northern Territory) and the deserts of Western Australia (Fig. 1).
etymology
Etymology. Yirratji, Warlpiri (Aboriginal dialect of the Alice Springs area) word for the local Pig-footed Bandicoot.
materials_examined
Holotype. NMV C 468, adult male, spirit specimen, with associated skull and dentaries, from Northern Territory. Paratype. MNHN ZM MO- 1853 - 824, taxidermy, tentatively associated with MNHN ZM AC- 1880 - 422, skull and dentaries; NHMUK ZD 1857.10. 24.19, juvenile, partial skull and dentaries; NMV C 469, adult male, spirit specimen; NMV C 470, adult male, spirit specimen with associated skull and dentaries; NMV C 471, juvenile male, spirit specimen; NMV C 5857, adult female, spirit specimen; NMV C 5858, adult male, spirit specimen; NMV C 5859, pouch young female, spirit specimen; NMV C 5860, adult female, spirit specimen; NMV C 5861, adult female, spirit specimen; SAMA M 1618, adult male, study skin with associated skull and dentaries; SAMA M 2425, adult female, taxidermy; SAMA M 2426, adult female, taxidermy; SAMA M 3971, juvenile female, spirit specimen with associated skull and dentaries. Referred specimens (modern). MAGNT U 1814, left dentary; SAMA M 3997, three spirit preserved pouch young. Referred specimens (fossil). From Cattle Camp, QMF 55183, right M 1; from Muldiva Cave, QMF 55215, right M 1 with broken talon, QMF 55216, right broken M 3; from Broken River, Left Wing unit 2, QMF 58985, right m 1; Dusty Drain, QMF 58991, left M 1; Big Ho, QMF 58992, right M 2; QMF 58993, left M 3; QMF 58990, left m 1; Beehive, QMF 58987, left maxilla with dP 3, P 3, M 1 – 2; QMF 58988, right broken M 1; QMF 58986, left M 1 stylar shelf; QMF 58989, Left M 2 / 3; Geologists’ Find Cave, QMF 58996, right M 1; Rock On A Rock passage (Beehive Cave), QMF 58994, right m 2; QMF 58995, right m 3; from Puntutjarpu, WAM A 18624, left edentulous maxilla, A 20810, left maxilla with broken M 3, A 20575, left edentulous dentary; from Chambers Gorge, J Cave, CHG. 1.2.4 a, partial skull; CHG. 1.2.4 b, left maxilla with P 1 – 2; CHG. 1.2.4 c, right edentulous dentary; CHG. 1.2.4 d, left dentary with m 4 erupting; CHG. 1.2.4 e, right dentary with m 4 erupting; D Cave, CHG. 6.2.3 a, right edentulous dentary; CHG. 6.2.3 b, left dentary with p 1, p 2, m 1 – 2; CHG. 6.2.3 c, right dentary with m 2; CHG. 6.2.3 d, left dentary with m 1 – 3; CHG. 6.2.3 e, left edentulous dentary; CHG. 6.2.3 f, partial skull; CHG. 6.2.3 g, left maxilla with M 1; CHG. 6.2.3 h, right maxilla with P 3 erupting, M 1 – 3; CHG. 6.2.3 i, right maxilla with P 2 – 3, M 1; from Uluru, Cave above Fertility Cave, KJT 0001, right broken M 3; KJT 0002, broken left edentulous maxilla; Ikari Cave, KJT 0003, right broken molar; from Kintyre Range, sample 9, KJT 0004, right edentulous dentary; sample 1 B, KJT 0005, right edentulous dentary, KJT 0006, right edentulous maxilla; sample 5, KJT 0007, left edentulous maxilla; KJT 0008, right dentary with roots of p 1; from Gibson Desert, Manton Knob, KJT 0017, left maxilla with M 1 – 2; KJT 0018 – KJT 0019, right edentulous dentary; Mount Johnson, KJT 0037, right maxilla with P 2, M 1; KJT 0038, left maxilla with P 2, dP 3, M 1 – 2; KJT 0039, left edentulous maxilla; KJT 0040, left edentulous dentary; KJT 0041, left p 1; KJT 0042, right p 2; KJT 0043, left m 1; KJT 0044, right m 2; KJT 0045, right m 4; KJT 0046, right m 1; KJT 0047, left m 2 talonid; KJT 0048, right m 3; KJT 0049, left edentulous dentary.
Name
- Homonyms
- Chaeropus yirratji Travouillon 2019