Strange Fossil Hints at Life After Mass Extinction
A new marine reptile has given scientists a window into the evolutionary period just after the worst loss of life the planet has ever known.
A fossil from a newly discovered animal that didn't look like it was supposed to has given scientists a window into the evolutionary period just after the worst mass extinction event the planet has ever known.
The new species, an ichthyosaur named Sclerocormus parviceps, was a marine reptile dating to the Lower Triassic, and it looked nothing like other ichthyosaurs scientists have studied.
Ichthyosaurs were marine reptiles that lived at the same time as Earth's earliest dinosaurs. Most had dolphin-like forms – strong tail fin, long telltale snout and sleek body. But the new animal had a stubby snout and a long tail - sans the big fin at the end.
Stranger still, ichthyosaurs typically had ample teeth for catching food, but Sclerocormus parviceps had no teeth at all. The researchers think its snout was built for sucking in food like a needle drawing blood.
The fossil dates to the time just after the Permian-Triassic event, which took out nearly all marine species and the vast majority of terrestrial vertebrates. Scientists had thought it was slow going for marine reptiles rebounding from that period, with evolutionary processes unfolding slowly.
However, the new fossil, looking nothing like its ancient relatives, challenges those notions.
"Sclerocormus tells us that ichthyosauriforms evolved and diversified rapidly at the end of the Lower Triassic period," said study co-author Olivier Rieppel, of The Field Museum, in a statement.
"We don't have many marine reptile fossils from this period," Rieppel added, "so this specimen is important because it suggests that there's diversity that hasn't been uncovered yet."
Rieppel said the new reptile offered a peek at real-world evolution in action.
"Darwin's model of evolution consists of small, gradual changes over a long period of time, and that's not quite what we're seeing here," he said. "These ichthyosauriforms seem to have evolved very quickly, in short bursts of lots of change, in leaps and bounds."
The museum biology curator thinks the find can help us better understand what life does when it needs to rebound.
"We're in a mass extinction right now. Not one caused by volcanoes or meteorites but by humans," Rieppel said. "While the extinction 250 million years ago won't tell us how to solve what's going on today, it does bear on the evolutionary theory at work. How do we understand the recovery and rebuilding of a food chain, of an ecosystem? How does that get fixed, and what comes first?"
Rieppel is part of an international team of scientists that worked on the study, which has been published in the journal Scientific Reports.
Shown is Sclerocormus parviceps, the newly described marine reptile.
Amphibians, such as the Zorro bubble-nest frog, are widely believed to be the most endangered class of animals on the planet. Nearly one-third of all the world's amphibians are close to extinction. The declines are among the most critical threats to global biodiversity. While researchers continue to study why so many amphibians have been dying out since the 1980s, possible causes include disease, habitat destruction and modification, exploitation, pollution, pesticide use, introduced non-native species, and ultraviolet-B radiation.
Six amphibians, including the Perereca, shown here, made the list of 15. The researchers determined that the animals' low chances for survival are due to several factors: * High probability of its habitat becoming urbanized * Political instability at the site * High cost of habitat protection and management * A low opportunity of establishing an insurance population in zoos due to high costs or lack of breeding expertise.
Because many of the animals on the list of 15 have such low populations, in many cases, not much is known about the species. Some are only documented in written accounts. Birgitte Svennevig of the University of Southern Denmark told Discovery News, "The 15 species are extremely rare, so we do not have photos of all of them. I am not even sure if photos of all of them exist." So some animals on the list, such as the Mount Lefo brush-furred mouse, are represented here by photos of closely related species. This photo shows the endangered mouse's close kin,
For the study, Conde and her team computed the cost of conserving 841 species of mammals, reptiles, birds and amphibians listed by the Alliance for Zero Extinction (AZE) as restricted to single sites and categorized as "endangered" or "critically endangered" on the IUCN Red List. "AZE sites are arguably the more irreplaceable category of important biodiversity conservation sites," Conde said. Ash's lark is one of the 15 most endangered animals on the planet. This photo shows the closely related species,
The estimated total cost to conserve the 841 animals included in the study was calculated to be over $1 billion total per year. That is if the animals are to be saved in their natural habitats. The estimated annual cost for management in zoos was $160 million. Costs, however, seem less daunting when each species is looked at individually. Hopefully efforts can still be boosted to support the conservation of animals like the Bay Lycian salamander, which is from Turkey and could go extinct during our lifetimes. Shown is the closely related Eastern newt.
The tropical pocket gopher is one of three mammals among the total list of 15 at-risk species. The researchers created a "conservation opportunity index," based on their study, with this small gopher winding up at the bottom of the list. It would take substantial funds and work to try and save it. "Although the cost seems high, safeguarding these species is essential if we want to reduce the extinction rate by 2020," co-author Hugh Possingham from the University of Queensland said.
Zino's petrel, a small bird native to the island of Madeira, is among the most endangered European seabirds.
Seabirds, such as this albatross, along with some amphibians, mammals and other birds are among the 15 species that are at greatest risk of becoming extinct very soon, a new study finds. The study, published in the journal Current Biology, found that these animals have a low chance of survival now in both the wild and in captivity, despite conservation measures. "Conservation opportunity evaluations like ours show the urgency of implementing management actions before it is too late," lead author Dalia Conde of the University of Southern Denmark said.
The Mascarene petrel from Reunion Island is threatened by pollution and predation by non-native animals.
While the report provides a realistic view on certain species' chances for survival and the probable cost to try and save them, the researchers hope that conservation efforts will improve. "Our exercise gives us hope for saving many highly endangered species from extinction, but actions need to be taken immediately and, for species restricted to one location (such as the frog
from Colombia), an integrative conservation approach is needed," said co-author John Fa.
The name Tahiti monarch might sound like a butterfly, but it's actually the common name for a very uncommon bird from French Polynesia. It's believed that there are fewer than 50 individuals remaining of this small bird, whose call has been likened to a beautiful melody played on a flute.
Native to Brazil, the Campo Grande tree frog's primary threat to survival is habitat loss.
Native to Mexico, the Chiapan climbing rat is now known only from one location in Tuxtla Gutierrez, Chiapas. Its habitat is being converted to agricultural and urban use. While rodents aren't viewed with much affection, the Chiapan climbing rat and all of the other animals on the list of 15 play critical roles in their ecosystems. When their numbers decrease or when a species dies out, the loss will ripple throughout the food chain, causing eventual adverse impacts to all of the other ecosystem members as well as to the habitat itself. Shown is a related species (right)
with an Alston's brown mouse.
The Santa Cruz dwarf frog is native to Brazil. More funding is needed to attempt to save it, but Possingham points out that costs are all relative. "When compared to global government spending on other sectors -- for example, U.S. defense spending, which is more than 500 times greater (than the estimated coast to conserve the 841 animals in the study) -- an investment in protecting high biodiversity value sites is minor," he said.
Wilkin's finch is now restricted to Inaccessible Island and Nightingale Island in the South Atlantic Ocean. The small bird was named after Australian polar explorer and ornithologist Captain Sir George Hubert Wilkins. Chances for future survival are very low. As co-author Markus Gusset of the World Association of Zoos and Aquariums concludes, "Actions that range from habitat protection to the establishment of insurance populations in zoos will be needed if we want to increase the chances of species' survival."