Innovatiocaris (meaning "innovation crab") is an extinct genus of radiodont from the early Cambrian Chengjiang Lagerstätte of Yunnan Province, China. The genus may contain two named species, I. maotianshanensis, known from a nearly complete young individual measuring up to 15.2 cm (6.0 in) and isolated frontal appendages, and I.? multispiniformis, known from a complete frontal appendage.[1]

Discovery and naming

Innovatiocaris maotianshanensis

The holotype specimen of Innovatiocaris maotianshanensis, ELRC 20001 was long considered in scientific literature as "Anomalocaris sp". or Anomalocaris saron (=Houcaris saron). However, in 2022, Zeng et al. described it as a new genus and species of radiodont. The holotype consists of the nearly complete remains of a young individual, preserved on a part and counterpart. Although a brief description of the specimen was provided by Chen et al. (1994),[2] and despite its popularity, it did not receive a detailed description until 2022. ELRC 20011 and 20012, additional specimens collected in 1990, consist of isolated frontal appendages. These were designated as paratypes. The specimens were collected from the Maotianshan Shale of the Yu'anshan Formation of Maotianshan, Chengjiang, in Yunnan Province, China.[1]

The generic name, "Innovatiocaris", combines the Latin word "innovatio", referencing "innovation" (honoring the 'innovative spirits" of Junyuan Chen, a scientist who contributed to the research of the Chengjiang Lagerstätte) and the Greek word καρίς (karís), meaning "shrimp" or "crab". The specific name, "maotianshanensis", references Maotianshan, the location where the holotype was discovered.[1]

Innovatiocaris? multispiniformis

Innovatiocaris? multispiniformis frontal appendage

NIGP 177621, the holotype of Innovatiocaris.? multispiniformis, was collected from the same locality as the I. maotianshanensis holotype. It consists of a complete frontal appendage. The appendage of I.? multispiniformis consists of 13 distal articulated podomeres, as opposed to the 11 podomeres found in I. maotianshanensis and I.? sp. This may be a unique feature or the result of incomplete preservation. The specific name, "multispiniformis", is derived from the roots "multi", meaning "multiple", and "spiniformis", meaning "spinous", in reference to the multiple spines on the frontal appendages.[1] A 2023 study argued that it forms a monophyletic clade with I.? sp. but not I. maotianshanensis, based on phylogenetic analyses.[3]

Innovatiocaris? sp.

An additional specimen, NIGP 177620, was assigned to Innovatiocaris? sp. by Zeng et al. (2022). It consists of a complete frontal appendage, preserved on a part and counterpart. The specimen was collected from the Maotianshan Shale Member of the Yu'anshan Formation in Jianshan, Haikou, Yunnan Province, China. It likely represents a distinct species from I. maotianshanensis.[1] This is further supported by a phylogenetic analysis from a 2023 study which suggested it forms a monophyletic clade with I.? multispiniformis but not I. maotianshanensis.[3]

Classification

Speculative life restoration

Zeng et al. (2022) noted that some of the anatomical characteristics of Inovatiocaris seem to indicate an affinity with the Hurdiidae, though it is otherwise more similar to non-hurdiids than to members of this family. The results of two different phylogenetic analyses by Zeng et al. (2022) are displayed in the cladograms below:[1]

References

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