快猫短视频

Ancient millipedes may have turned to scavenging animal remains out of desperation after the catastrophic plant die-off at the end of the Permian Period, around 252 million years ago. This could reveal how these usually herbivorous creatures survived after the planet鈥檚 most devastating mass extinction.

at the University of the Witwatersrand, Johannesburg, in South Africa and his colleagues working in sections of the Karoo basin in South Africa report that they have found fossils of early mammal relatives crawling with millipedes. They describe three vertebrate fossils dated to the early Triassic Period 鈥� just after the Permian extinction 鈥� that include invertebrate remains that seem to resemble millipedes.

The vertebrate fossils are all therapsids, a group containing the early ancestors of mammals, and include the small, short-snouted Scaloposaurus constrictus, the snub-nosed Lystrosaurus murrayi聽and another, unidentified species of Lystrosaurus.

Groenewald says that he and several colleagues all found millipede fossils in association with fossils of ancient mammal ancestors in the same region and began comparing notes. The strata in which they were working are rich in invertebrate fossils. And there have been several remarkable millipede discoveries.

鈥淚 started looking into millipede fossils, especially those that have been reported from the Karoo, and saw that what I had looked very similar,鈥� he says.

Previous has suggested that the corpses of turtle predecessors found in the same region were also fed upon by millipedes. Indeed, the fossils closely resemble each other.

鈥淎lthough there was vegetation during the Early Triassic it had changed dramatically and certainly did not contain lush foliage that we see in the Permian,鈥� says , also at the University of the Witwatersrand, Johannesburg. 鈥淭hese millipedes, if they were scavenging, would have eaten any species.鈥�

The vast majority of contemporary millipedes feed on decaying plant matter. But a handful have been observed feeding on dead animals 鈥� and the Permian extinction may have kicked that off.

Therapsids are known to have burrowed for shelter, and these ones may have fossilised after their burrows collapsed, entombing them and shielding them from large scavengers. The millipedes, too, are burrowers, and may have found a much-needed food source when they tunnelled up to a dead animal. The researchers acknowledge, though, that it is possible the millipedes were simply seeking shelter in the moist environment beneath the carcass.

The fact that millipede exoskeletons include calcium carbonate, rather than the chitin that predominates in insects, may have assisted in their fossil preservation, says at the American Museum of Natural History in New York. The hypothesis is 鈥減lausible鈥�, he says. 鈥淭hese could be millipedes and it could be that they are associated with the fossils because they were scavenging. But they also could have washed in.鈥�

He cautions that further research is needed to verify the identity of the potential millipedes. He is concerned by the lack of species identification and fine morphological analysis in the research 鈥� in particular, he cites the lack of identifiable legs on the millipede fossils.

鈥淭he next step in identification would be to look for ozopores [defensive glands] and ornamentation,鈥� says Groenewald, who believes that few, if any, other organisms from that environment possess the cylindrical, segmented form they observed.

These uncertainties highlight gaps in palaeontological studies: compared with vertebrates, invertebrates present a challenge because many species are poorly preserved. Still, the research offers a tantalising image of the post-Permian ecosystem, with organisms that survived a mass extinction potentially expanding their palates to adapt to radically altered conditions.