Alacaris is an extinct genus of fuxianhuiid arthropod known from the Cambrian period. It is only known from the type species Alacaris mirabilis (mistakenly named Alacaris multinoda in a figure in the describing paper) from the Cambrian Stage 3 aged Xiaoshiba Lagerstätte in Yunnan Province, China. It is morphologically similar to Chengjiangocaris, with which it forms a clade within Fuxianhuiida. Individuals reach a maximum of 12 centimetres in length, with a trunk consisting of 13 tergites. The basal region of the post-deutocerebral limbs were used in feeding, with the rhythmic movement of the legs guiding food towards the mouth along the food groove between the limbs, with gnathobases present near the mouth to macerate food.[1]

Alacaris
Temporal range: Cambrian Stage 3
YKLP 12269 largely complete specimen in lateral view
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Order: Fuxianhuiida
Family: Chengjiangocarididae
Genus: Alacaris
Yang et al, 2018
Type species
Alacaris mirabilis
Yang et al, 2018
Reconstruction of Alacaris, with Chengjiangocaris lower right
Various specimens of Alacaris

Phylogeny edit

Fuxianhuiida
Chengjiangocarididae

Alacaris

Chengjiangocaris

Fuxianhuiidae

References edit

  1. ^ Yang, Jie; Ortega-Hernández, Javier; Legg, David A.; Lan, Tian; Hou, Jin-bo; Zhang, Xi-guang (2018-02-01). "Early Cambrian fuxianhuiids from China reveal origin of the gnathobasic protopodite in euarthropods". Nature Communications. 9 (1): 470. Bibcode:2018NatCo...9..470Y. doi:10.1038/s41467-017-02754-z. ISSN 2041-1723. PMC 5794847. PMID 29391458.