Footprints on the Sands of Time Quiz

Answer: Tasmanian tiger

Also known as the thylacine, the Tasmanian tiger was the largest carnivorous marsupial until its extinction. All extant carnivorous marsupials are in the family Dasyuridae, and include the incorrect options.

The genus Badjcinus got its name from the words 'badj' (meaning expert hunter in the Wanyi language) and 'kynos' (meaning dog in Greek). The family name Thylacinidae has the same Greek root. B. turnbulli, the only known member of the genus, was quite small, probably about half the weight of a fully grown domestic cat. It is known to have been carnivorous from its dentition, and suspected to have been arboreal because its fossils have been found with a number of rainforest species.

Answer: Kangaroos

Macropod means big foot, and is used to describe animals with elongated hind feet that allow them to move by means of jumping: kangaroos, wallabies, pademelons, quokkas and some other less familiar groups. Fossils of a number of extinct macropods have been found at Riversleigh, including four species of Balbaroo.

The one selected for inclusion was identified in 2000, and given its nickname (and eventually its species name) because the upper canine teeth are over twice as long as the incisor teeth beside them, suggesting that they may have been visible even when the mouth was closed. From the skull size, B. fangaroo is thought to have been roughly the same size as a wallaby.

Answer: Mountain pygmy possum

The alpine/sub-alpine region, where the only extant species of the Burramys genus, B. parvus resides, is under serious pressure from warming temperatures, and the possums are currently only found in three small, isolated alpine locations. Conservationists have proposed that it may be possible to do a sort of reverse-engineering, and selectively breed the current animals to develop some of the traits from their ancestors, fitting them to live in a warmer environment than is currently viable.

These mouse-sized nocturnal cuties primarily feed on fruit and insects (especially the Bogong moth, which is also under threat due to habitat loss from human activity).

Answer: Bandicoots

The other contemporary peramelemorphians are bilbies (sometimes called rabbit-eared bandicooots), known to many from campaigns to promote them as a suitable Australian replacement for the Easter bunny. The three species of the extinct genus Bulungu, however, seem to be more closely related to bandicoots.

They were about the size of a mouse, and probably (based on the skull and jaw fragments found) omnivorous, like a modern bandicoot. Fossils identified as belonging to several species of Galadi, a carnivorous bandicoot, have also been found at Riversleigh.

In 2014, the oldest modern bandicoot, dating from around 15 million years ago, was identified, and placed in the genus Crash (yes, named after the video game).

Answer: Blunt hammer-like pre-molars

The Latin word 'malleus' (meaning hammer) and the Greek word 'dectes' (meaning biter) were chosen to describe these very unusual teeth. By comparison with other vertebrates, it has been suggested that the similarity to the dentition of the pink-tongued skink might mean that these ferret-sized marsupials of the Miocene were snail eaters. Two species have been identified, M. mirabilis and M. moenia.

This genus is the only one in their family, Malleodectidae. The other families in their order are Thylacinidae (thylacines, also all extinct), Myrmecobidae (with one living species, the numbat) and Dasyuridae (with about 75 living species).

Answer: Macroderma gigas (a ghost bat)

The ghost bat is the only extant species of the genus Macroderma. Bats are in the order Chiroptera, which includes a number of different families, and over 1000 species. All of them have a thin membrane connecting the digits of their forelimbs, allowing them to fly. Ghost bats, found in several places in the northern part of Australia, are the only Australian bats that eat vertebrates - birds, reptiles, even small mammals - in addition to insects and arachnids. Because they are carnivorous, they are sometimes called the false vampire bat.

The name of ghost bat refers to their color - their wings and skin are very pale, and their fur light grey - and from their hunting style, which involves hanging around in the dark waiting in ambush.

Answer: The adult has molars.

While all of these features distinguish the two genera, the name Obdurodon (Lasting tooth) refers to the persistence of hard pre-molar teeth in the adult; in the modern platypus, juveniles have them, but they drop out during maturation, and adults have horny pads.

The nearly-complete skull of O. dicksoni was the source for most of the reconstructive speculation about the genus, as its features allowed palaeontologists to identify possible feeding techniques (and hence a suitable habitat, etc.) and size estimates.

They are all described as giant platypuses - one species, O. tharalkooschild would have been more than double the size of a modern platypus, nearly a meter long.

Answer: Highly specialized diet of eucalyptus leaves

One of the most valuable aspects of the Riversleigh fossil record is that it covers a very long period of time, and shows how animal structures changed over that time, in line with the environmental changes reflected in the plant record. The fossil koala skulls have significantly different jaws and dentition that indicate they ate much softer vegetation than is the case for contemporary koalas; this is consistent with the evidence that they were living in rainforest areas at that time. More recent specimens have skulls whose shape has changed to be more modern, allowing for chewing of much tougher plant material while still retaining the structures associated with loud long-distance communication.

Although you will always be pulled up for referring to a koala as a koala bear (as they are not even remotely related to modern bears), it should be pointed out that their genus name comes from Greek words meaning pouch (or bag) and bear.

Answer: Marsupial lion

The 'leo' part of their name might have been a clue that these animals are called marsupial lions, although not felines in any way. Wakaleo (whose name means little lion, in a pidgin of local and Latin languages) was significantly smaller than other Thylacleonids, although their size increased over time. The oldest species, W. pitikantensis, lived abour 25 million years ago, adwas about the size of a modern cat, with well-developed carnivore teeth that indicate they would have been successful hunters on the order of a feral cat. The most recent species, W. alcootaensis, lived about 10 million years ago, and was the size of a modern lioness.

There has never been a marsupial hippopotamus, but fossils of Diprotodons show they were that size - and have been suggested as a possible source for stories about the legendary Bunyip.

Answer: Weirdodonta

With so little to go on, palaeontologists have virtually no idea what this animal looked like or how it behaved. But its teeth are remarkable. The genus name comes from a word in the local language meaning two moons, a reference to the fact that the chewing surface of the teeth has two crescent cusps that overlap each other. The order Weirdodonta is structured to have a single family (Yingabalanaridae) with a single genus (Yingabalanara) and a single species (Y. richardsoni). All members of the order are extinct (which is usually shown by writing a dagger in front of the name, which I am unable to replicate here). It is possible that future discovery of more fragments may lead to a better reconstruction, and the fragments may be reclassified into another group, but as of 2020 Weirdodonta it is.

Monotremata is the order for monotremes (platypus and echidna, the egg-laying mammals); Lagomorpha includes rabbits and hares; Cetacea is the order that contains whales and dolphins.