A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland.

A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia's rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards.

Adult phyllostomid (bat) enamel by scanning electron microscopy--with a note on dermopteran enamel.

This study assesses the enamel of five phyllostomids of differing feeding habits; only one example of the microchiropteran super-family Phyllostomoidae having previously been studied by SEM. A dermopteran was also examined to ascertain whether the enamel might reveal insectivore, chiropteran or primate characteristics. The five phyllostomids were found to display the additional crystallite discontinuity feature (minor boundary plane or seam) which is a major characteristic of all the bats we have so far examined - with the exception of two megachiropterans. The enamel of the four fruit and nectar feeders (Phyllostomus, Carollia, Glossophaga and Artibeus) is essentially similar and different to that of the blood feeder (Desmodus). The differentiating factor for the two groups is the poor degree of prism development in Desmodus; the prisms being restricted to the inner two thirds of the enamel over the cusps or sectorial ridge, and lacking in the greater part of the axial and the sulcular enamel. The poor prism development in the vampire bat raises interesting questions from both an ontological and a phylogenetic point of view. The dermopteran (Cynocephalus sp.) displays horse-shoe shaped prisms with associated minor boundary planes (seams); an appearance entirely similar to those microchiroptera we have examined. This finding could be advanced as evidence for a close phylogenetic relationship between the Dermoptera and Chiroptera as these features are not found to the same extent in insectivores or in primates; the other two orders to which dermopterans are assigned. The evolutionary significance of the seam feature is being studied further; it is very likely to be of importance in unravelling the history of mammalian enamel.

Chiropteran enamel structure.

We have examined sectioned and whole teeth of Hipposideros diadema in order to provide a baseline description of bat enamel at electron microscopy level. Intact and worn surfaces of whole teeth from representatives of all superfamilies of the suborder Microchiroptera, representatives of the suborder Megachiroptera, and the Ditjimanka fossil tooth have been surveyed. Whole chiropteran teeth lend themselves well to non-destructive SEM examination; all except Dobsonia sp. showing evidence of prismatic structure at the outer surface. The majority of prisms in chiropteran enamel are horse-shoe shaped becoming rounded and complete only towards the outer enamel surface. Prism packing is typically Pattern 3 near the enamel-dentine junction and Pattern 2 where the enamel is sufficiently thick. A major feature is the consistent presence of a minor boundary plane ("seam") at the open end of horse-shoe shaped prisms. Enamel tubules were found at the enamel-dentine junction of a number of species and consistently at the outer enamel surface of one, Macroglossus minimus. Further examination of embedded material is planned in order to quantify prism shape, prism packing and the disposition of tubules in chiropteran enamel.

A simple radioactive binding assay for the detection of rheumatoid factor in serum.

A simple radioactive binding assay for the detection of rheumatoid factor (RF-RBA) is described. Test sera are complement inactivated by incubation in 0.13 M ethylene diaminetetraacetic acid (EDTA) at 37 degrees C and then incubated with 125I-labelled heat-aggregated IgG. Rheumatoid factor bound, labelled IgG is separated from free by precipitation with 2.5% (w/v) polyethylene glycol 6000. Sera from 78 patients and 24 controls were tested in the RF-RBA assay and the results compared with those obtained by the rheumatoid latex test and the rheumaton test. 37 sera were positive and 59 sera were negative for rheumatoid factor by the 3 methods used. A positive correlation (r = 0.56, P less than 0.01) was observed between the rheumaton titre and the RF-RIA result.