Chaeropus ecaudatus occidentalis Gould 1845

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), pp. 1-69 : 16-31

Chaeropus ecaudatus occidentalis Gould 1845 new status

( Fig. 5–7 )

Holotype. NHMUK ZD 1844.7 .9.22, female, study skin with associated partial skull and dentaries, from Walyormourning near Goomallig, ~ 65 km (40 miles) north-east of Northam, Western Australia, collected by John Gilbert and presented to the museum by John Gould.

Referred specimens (modern). JM 770, partial skull (subfossil); WAM M49055 , right dentary with p2–3, m1–4; AMNH 196372, left maxilla and left and right dentary (do not belong to same individual).

Referred specimens (fossil). From the Nullarbor plains, Kestrel Cave 1, NHMUK PV M 102256, left maxilla with P3-M4 ; NHMUK PV M 102257, left dentary with p3 and m4 ; NHMUK PV M 102258, left edentulous dentary ; WAM 64.11 .66, crushed skull with left P3, M1, right P1, P3, M1, M3 ; WAM 68.11 .32, right dentary with m1 ; WAM 68.11 .33, right dentary with p3 ; WAM 68.11 .34, right dentary with p3, m4 ; WAM 68.11 .35, right dentary with p1, p3 ; WAM 68.11 .36, right dentary with p1 ; WAM 68.11.37-53, right edentulous dentary; WAM 68.11 .54, right dentary with m 4 in crypt ; WAM 68.11.55-56, right edentulous dentary; WAM 68.11 .57, right dentary with p 3 in crypt ; WAM 68.11 .58, left dentary with p2 ; WAM 68.11 .59, left dentary with m3 ; WAM 68.11 .60, right maxilla with M1 ; WAM 68.11 .61, right maxilla with P3, M1–4 ; WAM 68.11 .62, right maxilla with P1, M1–4 ; WAM 68.11 .63, right maxilla with M1 ; WAM 68.11 .64, right edentulous maxilla ; WAM 68.11 .65, right maxilla with P1 ; WAM 71.3 .141, skull with left and right P3, M1–4; Firestick Cave , WAM 66.3 .19, right edentulous dentary ; WAM 67.4 .324, left maxilla with M1–2 ; WAM 67.4 .325, left edentulous dentary ; WAM 67.4 .326, left dentary with c1 ; WAM 67.4 .327, left dentary with p1–2; Doline north of Eucla , WAM 67.10 .460, left dentary with m4 ; WAM 67.4 .338, right dentary with m3 ; WAM 67.4 .339, right edentulous dentary ; WAM 67.4 .340, left edentulous dentary; Old Homestead Cave , WAM 67.4 .78, right dentary with p2 ; WAM 67.4 .79, left dentary with p1, p3, m3–4 ; WAM 67.4 .80, left edentulous dentary ; WAM 67.4 .113, Skull with left M1, M3, right P2–3, M1–2; Blowhole , WAM 67.4 .313, skull with left and right M1 ; WAM 67.4 .314, right dentary with p3, m1, m3–4 ; WAM 67.4 .315, right dentary with p1, p3, m4 ; WAM 67.4 .316, left dentary with p1 ; WAM 67.4 .317, left dentary with m4 ; WAM 67.4 .318, left dentary with m 4 in crypt ; WAM 67.4 .319, left dentary with c1 ; WAM 67.4.320–323, left edentulous dentary; Warbla Cave , WAM 67.4 .328, right maxilla with M3 ; WAM 67.4.329–331, left edentulous dentary; WAM 67.4 .332, left dentary with p3 ; WAM 67.4 .333, left dentary with m3; Mullamullang Cave , WAM 67.4 .334, right maxilla with M3 ; WAM 67.4 .335, left edentulous dentary ; WAM 67.4.336–337, right edentulous dentary; WAM 68.3 .32, right dentary with m2–4; Dingo Cave , WAM 68.11.77–78, right edentulous dentary; Horseshoe Cave , UCMP 97482 , right dentary with m2–4 and right maxilla with P3 erupting, M1–2 ; UCMP 97483 , right dentary with p2, m2 ; WAM 68.11 .83, right edentulous dentary ; WAM 68.11 .84, left edentulous dentary ; WAM 71.5 .1, skull with associated dentaries ; WAM 72.1 .12, right maxilla with M1 ; WAM 72.1 .13, right dentary with p3, m3 ; WAM 72.1 .35, left and right edentulous dentary ; WAM 72.1 .49, left edentulous dentary ; WAM 72.1 .50, left dentary with p1, p3, m2–4 ; WAM 72.1 .64, left edentulous dentary ; WAM 72.1 .86, left edentulous dentary ; WAM 72.1 .101, left dentary with p3, m4 ; WAM 72.1 .102, right dentary with m4 ; WAM 72.1 .103, right dentary with p1 ; WAM 72.1 .104, left maxilla with M1 ; WAM 72.1 .105, right maxilla with P3 ; WAM 72.1 .106, right maxilla with M1–4 ; WAM 72.1 .124, right maxilla with M1–2, M4 ; WAM 72.1 .125, left maxilla with P3, M1, M3–4 ; WAM 72.1 .138, two right edentulous dentary ; WAM 72.1 .159, left maxilla with M2 ; WAM 72.1 .160, left dentary with m2 ; WAM 72.1 .195, left edentulous dentary ; WAM 72.1 .222, left edentulous dentary ; WAM 72.1 .247, left edentulous dentary ; WAM 72.1 .386, right edentulous dentary ; WAM 72.1 .444, left dentary with p3 erupting ; WAM 72.1 .464, left maxilla with M1–2 ; WAM 72.1 .487, right edentulous dentary ; WAM 72.1 .514, two right maxillae, one left dentary and three right dentaries ; WAM 72.1 .542, right maxilla with M1–3 and right edentulous dentary ; WAM 72.1 .561, right dentary with c1 ; WAM 72.1 .580, right dentary with m4 ; WAM 72.1 .581, left maxilla with M3–4 ; WAM 72.1 .582, right maxilla with P3, M1 ; WAM 72.1 .605, right dentary with m4 ; WAM 72.1 .627, left dentary with p2 ; WAM 72.1 .628, right maxilla with M1 ; WAM 72.1 .659, right maxilla with P3, M1–4 ; WAM 72.1.660–661, right maxilla with P3, M1; WAM 72.1 .662, left maxilla with P 3 in crypt ; WAM 72.1 .663, right maxilla with P 3 in crypt ; WAM 72.1 .664, right dentary with p2 ; WAM 72.1 .665, left dentary with p1 ; WAM 72.1 .666, left dentary with m3–4 ; WAM 72.1 .667, right dentary with p2, p 3 in crypt ; WAM 72.1 .707, right maxilla with M1 ; WAM 72.1 .708, left maxilla with M1 ; WAM 72.1 .728, right maxilla with M1, M3 ; WAM 72.1 .729, right maxilla with P3, M3–4 ; WAM 72.1 .730, right maxilla with M1, M4 ; WAM 72.1 .731, right maxilla with M1 ; WAM 72.1 .732, left maxilla with P3, M3 ; WAM 72.1 .764, left maxilla with P3, M1–4 ; WAM 72.1 .765, left maxilla with M1 ; WAM 72.1 .766, right maxilla with M1 ; WAM 72.1 .767, left dentary with p3, m4 ; WAM 72.1 .796, left dentary with p1, m2–4 ; WAM 72.1 .817, right dentary with p3 erupting ; WAM 72.1 .842, right maxilla with M1–2 ; WAM 72.1 .870, left dentary with p3 ; WAM 72.1 .895, skull with left and right M1–4 ; WAM 72.1 .896, left dentary with p3, m3–4 ; WAM 72.1 .921, left maxilla with M1 ; WAM 72.1 .955, right edentulous dentary ; WAM 72.1 .964, right maxilla with M1–4 ; WAM 72.1 .965, right dentary with p3, m4 ; WAM 72.1 .966, left dentary with p3 erupting ; WAM 72.1 .967, left edentulous dentary ; WAM 72.1 .986, right dentary with m3 ; WAM 72.1 .1012, left dentary with p3, m1–4 ; WAM 72.1 .1020, right edentulous dentary ; WAM 72.1 .1031, right m2 ; WAM 72.1 .1042, right P1 ; WAM 72.1 .1091, skull edentulous ; WAM 72.1 .1092, skull with left and right P3, M1–4 ; WAM 72.1 .1093, skull with left P3, M1, M4, right P3, M1 ; WAM 72.1 .1094, skull with left and right P3, M1–4 ; WAM 72.1 .1095, skull with left and right M1 ; WAM 72.1 .1096, right dentary with m4 ; WAM 73.3.19– 20, left edentulous dentary; WAM 73.3 .21, right dentary with p1–3, m2 ; WAM 73.3 .22, left maxilla with M3–4 ; WAM 73.3 .23, left maxilla with erupting P3, M1 ; WAM 73.3.24–27, right maxilla with M1; Cave south of Madura , WAM 68.3 .18, skull edentulous; Leaena’s Breath Cave , WAM 0 5.4.48, left maxilla with M2; from Wilgie Mia , layer 3 , WAM 73.1 .160, femur; talus below 5 , WAM 73.1 .168, left and right maxilla and associated left and right dentaries; layer 9/11 , WAM 73.1 .202, left and right maxilla and associated left and right dentaries; layer 14 , WAM 73.1 .220, leg bone; layer 15 , WAM 73.1 .221, tibia; layer 20 , WAM 73.1 .237, femur; layer 22 , WAM 73.1 .242, humerus; from Yaringa Station , WAM 82.7 .6, left edentulous dentary ; KJT0009 , right maxilla with M1–2 ; KJT0010 , left edentulous maxilla ; KJT0011 , right edentulous maxilla ; KJT0012 , left edentulous maxilla ; KJT0013 , right m3 ; KJT0014–0015 , right edentulous dentary ; KJT0033–0034 , right edentulous maxilla ; KJT0035 , right edentulous dentary ; KJT0036 , left edentulous dentary; from MacDonnell Ranges , WAM 83.11 .25, left edentulous dentary; from Mount Gould , WAM 17.1 .3, right dentary with p1, m4 talonid; from White Cloud Cliffs , KJT0024 , left dentary with m3 ; KJT0025 , left edentulous dentary ; KJT0026 , left dentary with m4 erupting ; KJT0027 , left edentulous dentary ; KJT0028–0029 , right edentulous dentary; from Winderie Station , KJT0056 , left maxilla with M1–2 ; KJT0057 , right maxilla with M1–2 ; KJT0058 , left edentulous dentary ; KJT0059 , right edentulous dentary; from Narring Range , KJT0060 , right edentulous maxilla ; KJT0061 , right M1 ; KJT0062 , left dentary with m4 erupting ; KJT0063 , right dentary with m4 erupting ; KJT0064 , right edentulous dentary ; KJT0065 , left dentary with m4 erupting; from Tallering Gorge , KJT0066 , left dentary and right edentulous maxilla ; KJT0067 , right dentary and left edentulous maxilla; from Tallering Hill , KJT0070 , left edentulous maxilla ; KJT0071 , right maxilla with M1–2 ; KJT0072 , right maxilla with M3 ; KJT0073–0074 , right edentulous maxilla ; KJT0075 , right maxilla P3 erupting ; KJT0076 , right edentulous dentary ; KJT0077 , left edentulous dentary ; KJT0078 , right edentulous dentary ; KJT0079–0080 , left edentulous dentary ; KJT0081 , right dentary with m4 erupting ; KJT0082 , right dentary with m2–4 ; KJT0083 , right maxilla with M1 ; KJT0084 , left edentulous dentary ; KJT0085–0087 , right edentulous dentary ; KJT0088 , left edentulous dentary ; KJT0089 , right edentulous dentary ; KJT0090 , left dentary with c1 ; KJT0091 , right dentary with p3 erupting, m3 ; KJT0092 , left dentary with p1, m2 ; KJT0093 , left dentary with c1, p1, p3, m3–4; from Mount Gibson Station , KJT0095 , left maxilla with M1; from Bimbijy Station , KJT0096 , right dentary with m1; from Burnerbinmah Station , KJT0097 , left edentulous maxilla ; KJT0098–0099 , right edentulous maxilla ; KJT0100–0101 , left maxilla with M1–2 ; KJT0102 , right maxilla with P2, M1–2 ; KJT0103–0104 , left edentulous dentary ; KJT0105–0106 , right edentulous dentary ; KJT0107 , right m3 ; KJT0108 – 0 109, left m1; from Mudan Hills , KJT0110 , left dentary with m4 erupting ; KJT0111 , left edentulous dentary ; KJT0112 , right dentary with m4 erupting ; KJT0113 , right dentary with m2, m4 erupting ; KJT0114 , left m1 ; KJT0115 , left m3 .

Emended diagnosis. Chaeropus ecaudatus occidentalis differs from C. e. ecaudatus in having grey pelage ventrally, longer ears (60 mm in C. e. occidentalis , 50–56 mm in C. e. ecaudatus ), larger medial accessory palatal fenestrae, thinner bridge between the maxillopalatine fenestrae and maxillary fenestrae, and smaller upper and lower premolars and molars on average. C. e. occidentalis differs from C. yirratji sp. nov. in having shorter hindfeet and tail; having maxillary fenestrae; having distinct medial accessory palatal fenestrae; having the paracone connecting to StB only on M1 (in unworn teeth); having a reduced metaconule on M1–3, making the molars more triangular in shape; carotid foramen opens ventrally; StD1 absent on M1; metacone of M4 is large; and the paracristid on m1 is continuous.

Remarks. The holotype is the only specimen that was collected alive in Western Australia. As a result, it is impossible to know the variation in external features that may have occurred in the Western Australian population. However, the features in the skull that are different from those seen in specimens on the eastern side of Australia can be easily compared to the many subfossil skulls recovered on the Nullarbor Plains (including western South Australia), and elsewhere in Western Australia (except in central and northern parts). Because those distinct features are consistent, we consider that they warrant distinction at subspecific level (see discussion).

……continued on the next page Distribution. Nullarbor Plains (Western Australia and South Australia), the Wheat Belt of Western Australia, and western Western Australia, south of the Pilbara ( Fig. 1 ).

Description. To avoid repetition, we have only described parts of the animal that differ from that of Chaeropus ecaudatus ecaudatus . The holotype is an adult female study skin, with an associated partial skull and dentaries. Pelage is dark chestnut dorsally, light brown laterally and grey ventrally. Ears are long (60 mm) and pointed. Head is rounded posteriorly with a short narrow snout. Forelimbs and hindlimbs are undistinguishable from that of C. e. ecaudatus . The tail is broken, likely to be missing some of its length.

The skull is broken and missing most of its posterior end. In dorsal and lateral view, the skull is undistinguishable from that of C. e. ecaudatus . In ventral view, the palate differs from that of C. e. ecaudatus in a number of ways. The medial accessory palatal fenestrae are very large, extending more anteriorly than in C. e. ecaudatus . A single large (larger than in C. e. ecaudatus ) foramen is anterior to the medial accessory palatal fenestra. The bridge of bone separating the maxillopalatine fenestrae from the maxillary fenestrae is much thinner than in C. e. ecaudatus . The upper and lower dentition does not differ in morphology to that of C. e. ecaudatus , but dental measurements are smaller on average (see result section).

Figures

FIGURE 1. Distribution map for specimens of Chaeropus. Chaeropus ecaudatus ecaudatus in blue, C. e. occidentalis in green, C. yirratji sp. nov. in red, C. sp. indet. in black. Square = modern specimens; circles = subfossils (Holocene or younger in age); stars = Pleistocene fossils; triangles = oral history from Burbidge et al. (1988).

FIGURE 5. Skin of Chaeropus ecaudatus occidentalis. a)–c), NHMUK ZD 1844.7.9.22, holotype, adult female. a), dorsal view; b), lateral view; c), ventral view. Scale = 7 cm.

FIGURE 6. Skulls and dentary of Chaeropus ecaudatus occidentalis. a)–f), NHMUK ZD 1844.7.9.22, holotype, adult female; g)–i), QM JM 770, adult subfossil; j), WAM 71.3.141, adult subfossil; k), WAM 71.5.1, adult subfossil. a), g), f), dorsal/ occlusal view; b), h), e), lateral/buccal view; c), i), j), k), ventral view; d), lingual view. Scale = 2 cm.

FIGURE 7. Upper and lower dentition of Chaeropus ecaudatus occidentalis. a), d), NHMUK ZD 1844.7.9.22, holotype, adult female; b), QM JM 770, adult subfossil; c), e), WAM 71.5.1, adult subfossil. a)–c), upper dentition in occlusal view; d)–e), lower dentition in occlusal view. Scale = 2mm.