Gorzelak Przemysław, Salamon Mariusz A, Ferré Bruno
Institute of Paleobiology, Polish Academy of Sciences, Warsaw.
Naturwissenschaften. 2011 Oct;98(10):903-8. doi: 10.1007/s00114-011-0838-4. Epub 2011 Sep 1.
Until recently, it has been assumed that pelagic crinoids, the roveacrinids (Roveacrinida, Crinoidea), became extinct during the Cretaceous-Paleogene boundary event. Recent finds of well-preserved roveacrinidal remains (brachials and radials) in the Danian (Early Paleogene) of Poland showed that they survived into the earliest Cenozoic. This group was thus characterized as a "dead clade walking". Here, we present fossil evidence that these pelagic crinoids survived in Poland until at least the Middle Miocene (Badenian, ca. 14 Myr ago)-more than 50 Myr after their supposed extinction. These Miocene roveacrinids constitute the first documented evidence of Roveacrinida in strata of Neogene age, thus prolonging the stratigraphic range of pelagic crinoids. This find characterizes the order as a "Lazarus taxon" rather than a "dead clade walking" group.
直到最近，人们一直认为浮游海百合，即游动海百合类（游动海百合目，海百合纲），在白垩纪-古近纪边界事件中灭绝。最近在波兰古近纪早期的达宁阶发现了保存完好的游动海百合类残骸（腕骨和辐板），表明它们存活到了最早的新生代。因此，这一类群被描述为“行尸走肉的分支”。在此，我们展示了化石证据，证明这些浮游海百合在波兰一直存活到至少中新世中期（巴登阶，约1400万年前）——在它们被认为灭绝之后超过5000万年。这些中新世的游动海百合类构成了新近纪地层中首个有记录的游动海百合目的证据，从而延长了浮游海百合的地层分布范围。这一发现表明该目是一个“拉撒路类群”，而非“行尸走肉的分支”类群。
