Палеонтологичид музейн сан хөмрөгөөс үлэг гүрвэлийн хамгийн эртний олдвороос 200 сая гаруй жилийн өмнөх үед хамаарах криноидын зөөлөн эдийн үлдэгдлийг олсон байна.
Оклахомагийн их сургуулийн судлаачид Монреалийн Палеонтологи, хувьслын музейд хадгалагдаж байсан Dendrocrinus simcoensis нэртэй далайн амьтны чулуужсан олдворыг судалжээ. Орчин үеийн далайн одтой төрөл төрөгсөд болох криноидууд нь 450 сая гаруй жилийн өмнө эртний шүрэн хадны экосистемд амьдарч байсан юм. Ихэнх криноидын олдвор зөвхөн хатуу ясан бүтцээс бүрддэг тул зөөлөн эд хадгалагдан үлдсэн нь шинжлэх ухааны хувьд нэн ховор тохиолдолд тооцогдоно.
Судлаачдын тогтоосноор, энэхүү олдворт агуулагдах тэмтрүүл хэлбэртэй эрхтэн нь криноидоос олдсон зөөлөн эдийн хоёр дахь тохиолдол бөгөөд хамгийн эртний нь юм. Палеонтологич Лена Коул зөөлөн эд ийм удаан хугацаанд хадгалагдахын тулд байгалийн хөргөгч эсвэл вакуум орчинтой төстэй нэн ховор нөхцөл бүрдсэн байх ёстойг онцолжээ.
Энэхүү олдвор нь эртний амьтдын хооллолтын арга барил болон тэдний амьдарч байсан орчныг судлахад чухал ач холбогдолтой юм. Судлаач Дэвид Райтын тайлбарласнаар, криноидын тэмтрүүлүүд нь хөхтөн амьтдын шүдтэй адил үүрэг гүйцэтгэдэг тул тэдгээрийн бүтэц, хэлбэр нь тухайн төрөл зүйл хэрхэн хооллож, ямар орчинд дасан зохицсоныг илэрхийлдэг байна.
Тус багийнхан музейн цуглуулгад хадгалагдаж буй сая сая олдворын дунд шинжлэх ухааны өндөр ач холбогдолтой олон нээлт хийх боломжтой байгааг тэмдэглэв. Ийм төрлийн судалгаа нь шинэ технологи, мэдлэгийг ашиглан хуучин олдворуудаас цоо шинэ мэдээлэл олж авах нь палеонтологийн салбарт хэр чухал болохыг харуулж байна.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Paleontologists at the University of Oklahoma have identified a crinoid fossil that preserves delicate soft tissue, something scientists almost never find. The specimen, Dendrocrinus simcoensis, holds tube feet that are the oldest soft tissue ever documented in a crinoid. It was found in a museum collection.
Crinoids are marine animals related to modern starfish. They often resemble underwater flowers, with branching arms extending from a central body. More than 450 million years ago, they were among the animals thriving in Earth’s earliest coral reefs, long before plants and animals had become widespread on land.
Scientists have discovered millions of crinoid fossils, but nearly all preserve only hard skeletal structures. Delicate body parts usually decay long before fossilization can occur, leaving major gaps in our understanding of how these creatures functioned.
A Fossil That Beat The Odds
The tube feet in this specimen are only the second known example of fossilized soft tissue in crinoids, and the oldest. Tube feet are small, flexible structures found in echinoderms, the group that includes starfish, sea urchins and crinoids. Because they are soft and easily destroyed after death, finding them in fossils is extraordinarily unusual.
According to Dr. Lena Cole, an OU paleontologist and assistant curator of invertebrate paleontology at the Sam Noble Oklahoma Museum of Natural History, the conditions needed are very specific.
“Soft tissues are only preserved when the environment acts almost like a natural refrigerator or vacuum-sealer — conditions that are incredibly rare. Preservation like this is truly one in a million,” Cole added. “Crinoid fossils number in the millions, and this is only the second time soft tissues have ever been found.”
Dr. David Wright, who co-authored the study, was particularly keen to stress the age, noted statement from the University of Oklahoma.
“It’s incredible these soft tissues have survived more than 450 million years,” he said. “For reference, these soft tissues are more than 200 million years older than the oldest dinosaur.”
What The Tube Feet Reveal About Feeding
Unlike the teeth and jaws many familiar animals use to eat, crinoids rely on specialized structures to capture food particles from seawater. Their tube feet play an important role in feeding and in how the animals interact with ocean currents. Size, arrangement and shape can differ between species, reflecting adaptations to particular habitats and feeding methods. As explained by Wright, there is a useful parallel with mammals.
“Since crinoid tube feet are used for feeding, you can think of them in a similar way to how we think about teeth in mammals,” he explained. “Differences in their structure tell us about what kinds of environments a species lived in and how it fed.”
Researchers also compared the fossil with crinoids living in today’s oceans and found notable anatomical differences.
“Comparisons with living crinoids show that the anatomy of this ancient species was very different,” Cole said. “This gives us new insight into how crinoids evolved and how their feeding strategies changed over hundreds of millions of years.”
Hiding In A Museum Drawer
The fossil was not unearthed on a remote expedition. It had been housed for years at Montréal’s Musée de paléontologie et de l’évolution, a small museum that operates entirely with support from community donations. Its value became apparent when Cole and Wright, both crinoid specialists, visited and examined the specimen more closely.
“New fossil discoveries ultimately come from fieldwork, but museum collections play a significant role in this kind of integrative research,” Wright said. “We don’t always know the full significance of the specimens we collect.”
Researchers don’t always know the full significance of what they collect, he said, and new technologies, ideas or expertise can find surprising ways to use existing specimens.
At the Sam Noble museum, they oversee invertebrate paleontology collections containing more than one million specimens, with more added every year. According to the University of Oklahoma, no individual researcher could examine every one in detail.
“There are simply too many fossils to study over one person’s career,” Wright said. “There’s more than a lifetime’s worth of discoveries waiting to be found.”
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