New ecdysozoan fossil embryos from the basal Cambrian of China

doi:10.1016/j.palaeo.2024.112635

NIGPAS OpenIR

	New ecdysozoan fossil embryos from the basal Cambrian of China
通讯作者	Zhang, Huaqiao(hqzhang@nigpas.ac.cn) ; Liu, Yunhuan(yunhuanl@chd.edu.cn)
	Liu, Mingjin 1; Xian, Xiaofeng 2; Zhang, Huaqiao2 ; Eriksson, Mats E.3; Liu, Yunhuan 1; Shao, Tiequan 1
	2025-02-01
发表期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY (IF:2.375[JCR-2017],2.779[5-Year])
ISSN	0031-0182
卷号	659 页码:12
摘要	Invertebrate embryos have relatively low fossilization potential; however, when preserved, they can offer crucial insights into the evolutionary developmental biology of extinct animals. Here we report new exceptionally preserved fossil embryos from the early Fortunian (early Cambrian) of China, which are assigned to two new taxa, Saccus xixiangensis gen. et sp. nov. and Saccus necopinus gen. et sp. nov. All specimens are three- dimensionally phosphatized, akin to the Orsten-type preservation. The embryos are enclosed within a thin and smooth envelope ranging in diameter from 730 mu m to 1 mm. The embryos have a bag-shaped body, a non- ciliated integument, radially arranged sclerites apically, and bilaterally arranged sclerites abapically, but lack any orifice, thus representing a developmental stage prior to the formation of a mouth or anus. The integument shows soft deformation, while the sclerites remain largely undeformed, suggesting that the sclerites are stiffer and likely cuticularized. The arrangement of the abapical sclerites imparts bilaterality, classifying these new embryos as bilaterians. Furthermore, the absence of cilia or cilium insertion sites and the presence of cuticularized sclerites suggest an ecdysozoan affinity. The relatively large embryo size indicates yolk-rich eggs, and the presence of cuticle implies that the embryos are in later embryonic stages, possibly close to hatching. In the absence of hatched specimens, it is inferred that these embryos undergo indirect development, hatching as lecithotrophic (yolk-feeding) larvae. In this case, the morphology of the juvenile and adult forms is uncertain due to metamorphosis during later growth. Alternatively, the embryos could undergo direct development, hatching as lecithotrophic juveniles, with both juveniles and adults potentially having a similar bag-shaped body without an introvert or paired limbs, closely reminiscent of Saccorhytus. This study expands our understanding of the morphological disparity and diversity of early Fortunian fossil embryos and ecdysozoans.
关键词	Fossil embryo Ecdysozoa Orsten-type fossils Kuanchuanpu formation Zhangjiagou section Cambrian Fortunian
DOI	10.1016/j.palaeo.2024.112635
收录类别	SCI
语种	英语
关键词[WOS]	ANIMAL EMBRYOS ; EVOLUTION ; MIDDLE ; CYCLONEURALIANS ; ZHANGJIAGOU ; TAPHONOMY ; RECORD ; LARVAE ; MOLT
资助项目	National Natural Science Foundation of China[42172020] ; National Natural Science Foundation of China[41921002] ; National Key Research and Development Program of China[2022YFF0802700] ; Swedish Research Council[2019-03516]
WOS研究方向	Physical Geography ; Geology ; Paleontology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS记录号	WOS:001383374800001
项目资助者	National Natural Science Foundation of China ; National Key Research and Development Program of China ; Swedish Research Council
出版者	ELSEVIER
文献类型	期刊论文
条目标识符	http://ir.nigpas.ac.cn/handle/332004/44725
专题	中国科学院南京地质古生物研究所
通讯作者	Zhang, Huaqiao; Liu, Yunhuan
作者单位	1.Changan Univ, Sch Earth Sci & Resources, Xian 710054, Peoples R China 2.Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, State Key Lab Palaeobiol & Stratig, Nanjing 210008, Peoples R China 3.Lund Univ, Dept Geol, Solvegatan 12, SE-22362 Lund, Sweden
通讯作者单位	中国科学院南京地质古生物研究所
推荐引用方式 GB/T 7714	Liu, Mingjin,Xian, Xiaofeng,Zhang, Huaqiao,et al. New ecdysozoan fossil embryos from the basal Cambrian of China[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2025,659:12.
APA	Liu, Mingjin,Xian, Xiaofeng,Zhang, Huaqiao,Eriksson, Mats E.,Liu, Yunhuan,&Shao, Tiequan.(2025).New ecdysozoan fossil embryos from the basal Cambrian of China.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,659,12.
MLA	Liu, Mingjin,et al."New ecdysozoan fossil embryos from the basal Cambrian of China".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 659(2025):12.