Wururoo
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| Wururoo | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Infraclass: | Marsupialia |
| Order: | Diprotodontia |
| Family: | †Balbaridae |
| Genus: | †Wururoo Cooke, 1997 |
| Species: | †W. dayamayi |
| Binomial name | |
| †Wururoo dayamayi Cooke, 1997 | |
Wururoo is an extinct genus of balbarid macropod known from the Late Oligocene of northeastern Australia. The genus contains a single species, Wururoo dayamayi, known from a single lower jaw bone collected at the Riversleigh World Heritage Area in Queensland. This taxon might represent a junior synonym of Balbaroo. Like most balbarids, it had a folivorous (leaf-based) diet.
The holotype and only known specimen of Wururoo, QM F19820, was recovered from the Late Oligocene-aged White Hunter Site of the Riversleigh World Heritage Area, in the Boodjamulla National Park, north-western Queensland. The specimen consists of a fragment of the right dentary preserving a lower premolar and all four lower molars. The remains were described and named as a new genus and species of macropod by Australian palaeontologist Bernard Cooke in 1997, alongside a new species of Nambaroo.[1] Fossil material belonging to two additional species of Wururoo was reported from several Early Miocene deposits at Riversleigh, but were later referred to the closely related Balbaroo fangaroo.[2][3]
The generic epithet, Wururoo, is a combination of the Mayabic word "wuru", meaning long ago, and the diminutive word for kangaroo. The specific epithet, dayamayi, combines the Waanyi words "daya", meaning chop, and "mayi", meaning tooth, in reference to its tall, blade-like premolar.[1]
A study published in 2014 suggested that the species might potentially be a junior synonym of Balbaroo gregoriensis, but stated that more specimens were needed to test this proposal.[3]
Description
The holotype dentary of Wururoo is at its deepest beneath the third and fourth lower molars. A short gap, or diastema, is present between the third lower premolar and first lower incisor, with a low ridge running along its entire length. Two small mental foramina are present on the horizontal ramus, one below and slightly in front of the premolar and the other below the back half of the second molar. The masseteric canal extends far forwards until it reaches the front of the second molar, where the remainder of the canal is blocked by undissolved matrix. On the lingual (inner; towards the tongue) side of the dentary, the mandibular symphysis extends backwards until it is below the midpoint of the premolar.[1] The lower premolar of Wururoo shares several similarities with that of Balbaroo fangaroo, in that they are both relatively large, plagiaulacoid, almond-shaped in occlusal view (or top view of the tooth enamel) and have six cuspids, with five of them having associated transcristae.[3] Like all other balbarids, its molars are lophodont, meaning that they have transverse enamel ridges.[1] The first lower molars possesses a very low metaconid, a feature also seen in Balbaroo gregoriensis. It was previously thought that Wururoo could be distinguished from other balbarids by the presence of a protostylid crest running down from the apex of the protoconid on the first lower molar. However, it is variably expressed in B. fangaroo, specifically in unworn juvenile and some less-worn adult specimens.[3]