科学 · 古代の尾の自切琥珀のトカゲの尾が、9900万年前の逃避機構を明らかにする仕組み執筆 2026年10月26日 0:01 UTC視聴文字起こし0:07Amber preserves a lizard's tail.0:09Release anatomy from roughly ninety nine million years ago.0:12Researchers say the tissue supports self detachment and escape mechanism living0:16lizards still use.0:18The evidence fits inside an amber piece just eighteen millimeters long.0:22What can that tiny tail tell us about how the animal let go?0:24Dola Fabricant spotted the tail in a museum collection.0:28The student was working with supervisor Leonidas Romanos Davernaglu at Tel Aviv0:32University.0:33The specimen was already held at the university's Steinhardt Museum of Natural0:37History, where its preserved anatomy became the focus of investigation.0:40The amber piece measures eighteen millimeters or zero point seven inches.0:44That's the size of the amber surrounding the fossil.0:47The scientific value comes from something smaller still, the tissue preserved where0:51the tail separated.0:52The amber comes from northern Myanmar.0:54The museum collection is in Tel Aviv, Israel, that places this tiny fossil in two0:58settings: its ancient environment and the institution where researchers recognize1:02the significance of its anatomy.1:04Ahmed Nasser examined the fossil without cutting it open.1:06The Volcani Institute specialist performed the scans at the team's request.1:10Fabrican Davernaglu and Nasser worked with co-author Apostolos Christopoulos, who1:14also discussed why the animal's exact species remains unknown.1:17A detached tail alone leaves several explanations open.1:20An injury can also separate a tail from an animal.1:23The researchers needed to examine the anatomy at the break to understand how this1:26one came away.1:27X-rays revealed tissue hidden inside the opaque amber.1:30The technique is called micro, computed tomography or micro CT.1:34It produced three-dimensional reconstructions, allowing the team to examine the1:38separation point while leaving the specimen intact.1:40The tail's outer form and musculature are well preserved.1:43Its internal structures, though, are completely mineralized, preventing examination1:47of skeletal features.1:48What survives is recognizable anatomical organization through fossilization rather1:52than unchanged living tissue.1:54A symmetrical ring of tissue survives at the separation point.1:57The researchers say it matches muscle rosettes involved in tail shedding in living2:01lizards.2:01They also found a clean break without typical crushing patterns.2:04Together, those clues support their interpretation of self, detachment.2:08Biologists call that mechanism caudal autotomy, meaning self, detachment of the2:13tail.2:13In living lizards, physical contact from a predator can trigger the release.2:16The word deliberate describes the release mechanism here.2:19It doesn't tell us what this ancient animal was thinking.2:22The amber is roughly ninety, nine million years old.2:25That places the mechanism in the late Cretaceous.2:27Earlier fossil interpretations drew on fracture planes and bones.2:31This specimen adds direct evidence from the preserved soft tissue anatomy involved2:35in release.2:35The finding shows the mechanism existed by then.2:38Its evolutionary beginnings could be older.2:40The university announced the discovery on October twenty-five, two thousand and2:43twenty-six, and the study appears in the journal's two thousand and twenty-six2:47volume.2:47Living lizards can escape a grasp by releasing their tails.2:50Movement of the discarded portion can also distract a predator.2:53Regeneration is a separate later process.2:56This fossil gives researchers evidence of the release mechanism itself.2:59The exact species and the immediate trigger remain unknown.3:02The animal may have shed its tail while pulling free of sticky resin, or it may have3:06released the tail against a predator before the discarded piece became trapped.3:09The preserved anatomy supports self detachment, but the lizard's fate remains3:14unknown.記事を読むストーリーの時系列HeyDexショート動画 ↗
