Giant Marsupial Graveyard Unearthed in Australia
by Jennifer Welsh
A treasure trove of giant marsupial fossils — including one named Kenny — has been uncovered in Australia. The bones will help researchers better understand these ancient pouched mammals, and figure out why they went extinct.
These giant marsupials of the genus Diprotodon lived in what is now Australia from about 1.6 million years ago up until about 25,000 to 50,000 years ago. They roamed the continent eating vegetation, but died out when large numbers of humansmoved into the area. Being such enormous creatures — standing at 13 feet (4 meters) and weighing up to 6,100 pounds (2,800 kilograms) — Diprotodon likely had to scarf down as much as 330 pounds (150 kg) of vegetation daily, research has found.
The researchers uncovered the remains of about 50 Diprotodon individuals at BHP Billiton Mitsui Coal’s South Walker Creek mine site in Queensland where researchers have been excavating since 2009. The fossils date back 100,000 to 200,000 years ago, the researchers told the BBC…
(read more: Live Science)
(image: extinct marsupial mega-herbivore, Diprotodon optatum, by Peter Murray )
Reconstruction of Ctenoimbricata spinosa gen. et sp. nov.
“Echinoderms are unique in being pentaradiate, having diverged from the ancestral bilaterian body plan more radically than any other animal phylum. This transformation arises during ontogeny, as echinoderm larvae are initially bilateral, then pass through an asymmetric phase, before giving rise to the pentaradiate adult. Many fossil echinoderms are radial and a few are asymmetric, but until now none have been described that show the original bilaterian stage in echinoderm evolution. Here we report new fossils from the early middle Cambrian of southern Europe that are the first echinoderms with a fully bilaterian body plan as adults. Morphologically they are intermediate between two of the most basal classes, the Ctenocystoidea and Cincta. This provides a root for all echinoderms and confirms that the earliest members were deposit feeders not suspension feeders.”
Zamora S, Rahman IA, Smith AB (2012) Plated Cambrian Bilaterians Reveal the Earliest Stages of Echinoderm Evolution. PLoS ONE 7(6): e38296. doi:10.1371/journal.pone.0038296