It is scaly and armored, hiding a secret identity.Dasypus novemucinctusA unique mammal found from southern Illinois to northern Argentina, the iguana isn’t actually one species. This unusual group of animals is made up of four different species. the study Published in the journal June Systematic biology.
Armadillos belong to the Xenarthra family of animals that also includes anteaters and sloths, native to the Americas. They are a traditional symbol of the American South, especially the state of Texas, and a beloved mascot for all things American. Sports Teams To Chain RestaurantIn fact, they arrived there relatively recently: the armored animals first settled north of the Rio Grande. Late 1800safter crossing the river of their own accord. Around the same time, reptile-like mammals were introduced to Florida by humans. They have continued to spread ever since. In recent years, armadillo populations have spread as far north as Illinois and Indiana, and as far east as VirginiaHow and why they were able to spread so widely remains a mystery, but we are now learning more about the different species of these strange creatures.
Through genetic and trait analysis, biologists say they have discovered hidden variants hiding under the oversimplified umbrella of the armadillo clade. Until now, there are 21 recognized species of armadillos, and splitting one lineage into four would increase armadillo diversity by about 14%. In addition to broadening the armadillo family tree, the new division could have important conservation implications as scientists consider the four species in a new context.
Two of the newly defined species are: Past researchOne of the species lives up to the name and description of a typical cricket armadillo, and the fourth is a species that has never been described before (the first for armadillos in 30 years).
This news means that the name of the state animal of Texas will be changed.Mexican wolf) occupies the northernmost part of the former range of the blue-and-white armadillo, which stretches from Costa Rica to the Americas. Dasypus fenestratus They live in the western Andes from Costa Rica through Ecuador, northern Colombia and northern Venezuela. Only the southernmost part of the stick insect’s former range, which included most of South America, remains as the official habitat of the stick armadillo.
Finally, the Guiana Navajo armadillo (Dasypus guianensis). This previously undescribed species lives in the Guinea Shield, a 1.7 billion year old geological structure made up of multiple highlands that spans parts of Guyana, Suriname, French Guiana and Venezuela.
“The distribution of each species is now much more restricted.” Anderson Feijoo“This discovery is a testament to the work of the zoologists who have worked on the study,” said Robert G. [these animals’] “Ecological requirements,” he added, mean that animals previously thought to be highly adaptable, with large ranges and no risk of habitat loss will now be reconsidered four times: different species have different habitat needs and resources that may not be met in some places.
“We now have to reassess each of these four different organisations.” Frederick DelschueckDelschuq is an evolutionary biologist at the French National Center for Scientific Research and lead author of the study. Delschuq is also part of the International Union for Conservation of Nature (IUCN) expert group responsible for classifying where armadillo species fall on the IUCN Red List. Delschuq is eager to evaluate each of the four newly classified species, but said he’s not immediately concerned about any of them, given how often they’re found littering roads, suggesting that they’re probably “quite numerous.”
Unfortunately for the armadillos, the mammals’ tendency to get buried under car tires is actually a blessing for the researchers: Of the 80 total armadillo specimens, just over half were dried specimens, mostly from museums, but 34 specimens were collected fresh in the field, “mostly from roadkill,” Delsac says.
The scientists extracted both mitochondrial and nuclear DNA from fragments of armadillos taken from across the range of what was once nine stripes. They performed multiple analyses to analyze the precise relationships of the 80 study animals. In one type of analysis, they repeatedly grouped individuals by genetic similarity and found that four clusters appeared again and again. In another type of analysis, they assessed gene flow between these clusters. They found some evidence of interbreeding, but these cases were rare and were only observed at the range boundaries of each group. “All this supports the idea that these four lineages are separate species,” the researchers say. Mathilde Barthesis lead study author, who recently completed his PhD in molecular evolution at the University of Montpellier in France.
It’s unclear how long ago the different armadillo lineages diverged, but Delsac said low levels of interbreeding suggest it was likely relatively recent on the evolutionary scale.
The thorough genetic analysis was essential to discovering and defining the species divergence, because the four species are, for the most part, visually similar to one another. At first glance, or in the field, “it’s very difficult to tell them apart,” Feijó says. But subtle differences in skull shape allow experts to distinguish the skeletal remains, Delscu says. And the new Guiana species is the most different from the others. According to Feijó’s formal description, the species is slightly larger, has a hairless shell, has one more vertebrate, and has a domed, thicker skull. Further research may reveal that the species diverge in other ways, too, such as behavior or feeding habits.
The new discovery was 25 years in the making and builds on previous research into armadillo diversity. But it still has limitations: DNA in museum specimens is often contaminated and degraded. Barthe says the scientists took “special care” to reduce the effects of that potential contamination and filter the data, but some oddities may have been overlooked. Still, none of the researchers expect their proposal to generate much controversy. “The evidence is mounting and has led us to this final conclusion,” Feijo says.
There’s also a lot still to learn about mammalian biology. “Usually people think of mammals as a very well-known group,” Feijo says, “but the reality is we’re only just starting to learn.” Today, there are four newly defined species; tomorrow, he says, there will probably be even more.
