Abstract
The Cambrian radiation of euarthropods can be attributed to an adaptable body plan. Sophisticated brains and specialized feeding appendages, which are elaborations of serially repeated organ systems and jointed appendages, underpin the dominance of Euarthropoda in a broad suite of ecological settings. The origin of the euarthropod body plan from a grade of vermiform taxa with hydrostatic lobopodous appendages ('lobopodian worms') is founded on data from Burgess Shale-type fossils. However, the compaction associated with such preservation obscures internal anatomy . Phosphatized microfossils provide a complementary three-dimensional perspective on early crown group euarthropods , but few lobopodians . Here we describe the internal and external anatomy of a three-dimensionally preserved euarthropod larva with lobopods, midgut glands and a sophisticated head. The architecture of the nervous system informs the early configuration of the euarthropod brain and its associated appendages and sensory organs, clarifying homologies across Panarthropoda. The deep evolutionary position of Youti yuanshi gen. et sp. nov. informs the sequence of character acquisition during arthropod evolution, demonstrating a deep origin of sophisticated haemolymph circulatory systems, and illuminating the internal anatomical changes that propelled the rise and diversification of this enduringly successful group.
Original language | English |
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Pages (from-to) | 120-126 |
Number of pages | 7 |
Journal | Nature |
Volume | 633 |
Early online date | 31 Jul 2024 |
DOIs | |
Publication status | Published - 5 Sept 2024 |
Funding
The authors thank H.-Q. Zhang for preparation of fossil material, and G. Edgecombe for comments on an early draft of the manuscript. M. Pankhurst and A. Bodey assisted with XCT analysis at Diamond Light Source (under proposal MT15461). We acknowledge funding from Dong Energy, the Leverhulme Trust (Research Project Grant 2019-223) and NERC (NE/M018687/2).
Keywords
- Cambrian euarthropods
- euarthropod larva
- arthropod evolution