Эрдэмтэд Австралийн Квинсленд мужаас олдсон жижиг хэмжээтэй чулуужсан олдвор дээр тулгуурлан махчин уутат амьтдын хувьслын түүхийг шинээр тодорхойллоо.
Шинээр нэрлэгдсэн Miyumba chrisdickmani хэмээх энэхүү амьтан нь ойролцоогоор 18 сая жилийн өмнө амьдарч байсан бөгөөд өнөөгийн хасгуй, Тасманийн чөтгөр зэрэг амьтдыг багтаадаг Dasyuridae овгийн хамгийн эртний гишүүн гэж тооцогдож байна. Шинэ Өмнөд Уэльсийн их сургуулийн судлаачид Риверслей дэлхийн өвийн бүсээс олдсон эрүүний хэлтэрхийнүүдийг микро-КТ сканнер ашиглан шинжилжээ. Шинжилгээгээр тус амьтан нь 23-33 грамм жинтэй, Миоцений эхэн үеийн ширэнгэн ойд амьдардаг жижиг махчин байсныг тогтоосон байна.
Судалгааны багийнхан шүдний бүтцэд хийсэн нарийвчилсан шинжилгээгээр Dasyuridae овогт хамаарах бүх амьтанд байдаг анатомийн онцлог шинжийг илрүүлжээ. Энэхүү олдвор нь тус овгийн анхны найдвартай лавлагаа болж байгаа бөгөөд генетикийн өгөгдлүүдтэй харьцуулан үзэхэд уг бүлэг 25.6 сая жилийн өмнө үүссэн байх магадлалтай гэж үзэж байна. Энэ нь өмнөх таамаглалаас гурван сая жилээр эрт хугацаа юм.
Miyumba chrisdickmani нь уг овгийн хамгийн эртний бөгөөд анхдагч хэлбэр болох нь тогтоогдсон нь хувьслын түүхийг ойлгоход чухал ач холбогдолтой. Түүнчлэн уг олдвор нь эртний Австрали болон Шинэ Гвинейн экосистемийн холбоог харуулж байна. Судлаачдын үзэж буйгаар, энэхүү амьтан нь эрт цагт өргөн тархацтай байсан ч хожим нь зөвхөн Шинэ Гвинейн ширэнгэн ойд үлдсэн уутат амьтдын нэгэн жишээ байж болох юм.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A tiny fossil found in Queensland has changed what scientists know about the early history of Australia’s carnivorous marsupials. The newly described species Miyumba chrisdickmani lived around 18 million years ago and is now considered the oldest known member of the Dasyuridae family, which includes today’s quolls, Tasmanian devils and antechinuses.
The discovery comes from the Riversleigh World Heritage Area in northwestern Queensland, one of Australia’s most important fossil sites. Researchers from the University of New South Wales studied several fossil jaw fragments found there, revealing new details about a group of marsupials whose early history has remained difficult to reconstruct.
During the Early Miocene, Miyumba chrisdickmani lived in rainforest environments and was a small predator weighing between 23 and 33 grams. Its size was comparable to modern antechinuses and dunnarts, showing that some of the earliest known dasyurids were already small, agile hunters.
As explained by the researchers, this family is now one of the most diverse groups of Australian marsupials, with 67 living species across 21 genera. Finding such an early member of the family gives scientists a clearer picture of how these animals began to evolve.
A Small Fossil with a Big Evolutionary Clue
The fossil remains consisted of partial lower jaws, but they contained valuable information. Scientists used micro-CT scanning to examine the teeth in detail and compared them with dozens of extinct and modern marsupial species.
The study, avaliable on Australian Zoologist revealed a dental feature that appears to be shared by all known dasyurids. This discovery provides the first reliable anatomical characteristic that can identify the entire family.
For years, scientists had struggled to recognize the earliest dasyurids because there was no clear physical trait separating them from closely related marsupials. The teeth now provide a new reference point for studying the group’s origins.
The researchers found that this species likely split from the rest of the dasyurids before all other known members of the family. This makes it the oldest and most primitive dasyurid discovered so far.
A Much Older Family than Scientists Thought
The discovery also changes the timeline of dasyurid evolution. By combining fossil evidence with genetic data from living species, researchers estimated that the wider dasyurid lineage appeared around 25.6 million years ago.
That date is about three million years earlier than previous estimates. The fossil record already included several later dasyurid species, but Miyumba chrisdickmani provides evidence that the family was present much earlier in Australia’s history.
“The fossil record contains 20 dasyurid species in eight genera that include living species and two genera that include only living species known from Australian Plio-Pleistocene deposits,” Dr. Timothy Churchill, the study’s lead author, and his colleagues from the University of New South Wales noted.
The new species helps fill a gap between the origins of the family and the more recent fossils that have been easier to identify. It also shows that early dasyurids were already living in rainforest habitats millions of years ago.
Scientists Uncover New Guinea’s Marsupial Mystery
The fossil also offers clues about the connection between ancient Australian ecosystems and today’s rainforest animals in New Guinea. Researchers found that Miyumba chrisdickmani shares dental similarities with modern rainforest-dwelling marsupials from New Guinea, including species from the genus Murexia.
“New Guinea has retained extensive rainforest cover since the Miocene, preserving a faunal assemblage that likely reflects the ecological structure of Sahul’s former lowland rainforests,” said the study authors.
The researchers also noted that New Guinea has kept large areas of rainforest since the Miocene, preserving animal communities that may reflect the ecosystems that once existed across Sahul, the ancient landmass connecting Australia and New Guinea.
They suggested that Miyumba chrisdickmani could be another example of a marsupial lineage that was once more widespread but later became limited to New Guinea.
Enjoyed this article? Subscribe to our free newsletter for engaging stories, exclusive content, and the latest news.
