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Data from: Fine-scale appendage structure of the Cambrian trilobitomorph Naraoia spinosa and its ontogenetic and ecological implications

Citation

Zhai, Dayou et al. (2019), Data from: Fine-scale appendage structure of the Cambrian trilobitomorph Naraoia spinosa and its ontogenetic and ecological implications, Dryad, Dataset, https://doi.org/10.5061/dryad.jdfn2z372

Abstract

Trilobitomorphs are a species-rich Palaeozoic arthropod assemblage that unites trilobites with several other lineages that share similar appendage structure. Post-embryonic development of the exoskeleton is well documented for some trilobitomorphs, especially trilobites, but little is known of the ontogeny of their soft parts, limiting understanding of their autecology. Here we document appendage structure of the Cambrian naraoiid trilobitomorph Naraoia spinosa by computed microtomography, resulting in three-dimensional reconstructions of appendages at both juvenile and adult stages. The adult has dense, strong spines on the protopods of post-antennal appendages, implying a predatory/scavenging behavior. Absence of such gnathobasic structures but instead tiny protopodal bristles and a number of endopodal setae suggests a detritus-feeding strategy for the juvenile. Our data add strong morphological evidence for ecological-niche shifting by Cambrian arthropods during their life cycles. A conserved number of appendages across the sampled developmental stages demonstrates that Naraoia ceased budding off new appendages by the mid-juvenile stage.

 

 

Methods

The specimens, which are presented as mud-stone slabs, were scanned with a GE Phoenix Nanotom m scanner, resulting in a set of tiff images for each scan. Slabs a and b of YKLP 11408 are each represented by 400 tiff images. YKLP 11409 is represented by 2200 tiff images. These tiff images can be further processed with 3D reconstruction software such as Drishti, Mimics and Dragonfly, to visualize the fossil structures.

Usage Notes

These are the micro-CT data that support the paper "Fine-scale appendage structure of the Cambrian trilobitomorph Naraoia spinosa and its ontogenetic and ecological implications", which has been accepted for publications in Proceedings B. The data for the two specimens (YKLP 11408 and YKLP 11409) described in that paper are presented here. The specimens were scanned with a GE Phoenix Nanotom m scanner. For more technical details please see Zhai et al. (2019, Proceedings B).

Anyone who is going to use these data for publication should contact Yu Liu (yu.liu@ynu.edu.cn) or Dayou Zhai (dyzhai@ynu.edu.cn). Please cite Zhai et al. (2019, Proceedings B, doi: http://dx.doi.org/10.1098/rspb.2019.2371).