Division of Earth Sciences, Korea Polar Research Institute, 26 Songdomirae-ro Yeonsu-gu, Incheon 21990, Republic of Korea.
University of Science and Technology, 217 Gajeong-ro, Daejeon 34113, Republic of Korea.
Sci Adv. 2024 Jan 5;10(1):eadi6678. doi: 10.1126/sciadv.adi6678. Epub 2024 Jan 3.
Chaetognaths, with their characteristic grasping spines, are the oldest known pelagic predators, found in the lowest Cambrian (Terreneuvian). Here, we describe a large stem chaetognath, gen. et sp. nov., from the lower Cambrian Sirius Passet Lagerstätte, which exhibits lateral and caudal fins, a distinct head region with long antennae and a jaw apparatus similar to . has previously been interpreted as a total-group chaetognathiferan, as either a stem-chaetognath or gnathostomulid. We show that shares a ventral ganglion with chaetognaths to the exclusion of other animal groups, firmly placing these fossils on the chaetognath stem. The large size (up to 30 cm) and gut contents in suggest that early chaetognaths occupied a higher trophic position in pelagic food chains than today.
齿形目动物具有特有的抓握刺，是已知最古老的远洋捕食者，可追溯到最低的寒武纪（特列涅乌阶）。在这里，我们描述了一种来自下寒武统 Sirius Passet 生物群的大型原始齿形目动物，gen. et sp. nov.，其具有侧鳍和尾鳍、明显的头部区域，长触角和类似于的颚器。以前被解释为总群齿形目动物，要么是原始齿形目动物，要么是颌口动物。我们表明，与其他动物群不同，与齿形目动物共享腹神经节，这将这些化石牢牢地置于齿形目动物的主干上。的大型尺寸（长达 30 厘米）和肠道内容物表明，早期的齿形目动物在远洋食物链中占据的营养位置比今天更高。
