An early Cambrian euarthropod with radiodont-like raptorial appendages

  title={An early Cambrian euarthropod with radiodont-like raptorial appendages},
  author={Han Zeng and Fangchen Zhao and Kecheng Niu and Maoyan Zhu and Diying Huang},
Resolving the early evolution of euarthropods is one of the most challenging problems in metazoan evolution 1 , 2 . Exceptionally preserved fossils from the Cambrian period have contributed important palaeontological data to deciphering this evolutionary process 3 , 4 . Phylogenetic studies have resolved Radiodonta (also known as anomalocaridids) as the closest group to all euarthropods that have frontalmost appendages on the second head segment (Deuteropoda) 5 – 9 . However, the… 

Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution

Phylogenetic analysis suggests that two specimens of opabiniid-like euarthropods with anterior proboscis from the Middle Ordovician Castle Bank Biota, Wales, UK may be sister to radiodonts and deuteropods, substantially extending the geographic and temporal range of Opabiniidae.

New multipodomerous appendages of stem-group euarthropods from the Cambrian (Stage 4) Guanshan Konservat-Lagerstätte

Two new euarthropods from the Cambrian Stage 4 Guanshan Biota of South China are reported, with Lihuacaris ferox appendages resembling the frontal appendages of radiodonts, as well as the post-oral endopods of chengjiangocaridid fuxianhuids and other deuteropods with well-documented raptorial/predatory habits.

A new euarthropod with large frontal appendages from the early Cambrian Chengjiang biota

We describe Fengzhengia mamingae gen. et sp. nov., a new euarthropod from the lower Cambrian (Series 2, Stage 3) Chengjiang Lagerstätte, Southwest China. Fengzhengia mamingae possesses prominent

Before trilobite legs: Pygmaclypeatus daziensis reconsidered and the ancestral appendicular organization of Cambrian artiopods

Pygmaclypeatus daziensis shows that appendage heteronomy is phylogenetically widespread within Artiopoda – the megadiverse clade that includes trilobites and their relatives with non-biomineralizing exoskeletons – and suggests that a single exopodite lobe with paddle-like lamellae is ancestral for this clade.

New opabiniid diversifies the weirdest wonders of the euarthropod lower stem group

The phylogenetic evidence expands opabiniids to multiple Cambrian Stages spanning approximately five million years and underscores the power of treespace visualization for resolving imperfectly preserved fossils and expanding the known diversity and spatiotemporal ranges within the euarthropod lower stem group.

New opabiniid diversifies the weirdest wonders of the euarthropod stem group

Once considered ‘weird wonders’ of the Cambrian, the emblematic Burgess Shale animals Anomalocaris and Opabinia are now recognized as lower stem-group euarthropods and have provided crucial data for

Fuxianhuiids are mandibulates and share affinities with total-group Myriapoda

In spite of their unrivalled ecological success, the origins of terrestrial mandibulates have long remained virtually unknown. In recent years, claims have been made based on phylogenetic results

The origin and evolution of the euarthropod labrum.

  • G. Budd
  • Biology, Environmental Science
    Arthropod structure & development
  • 2021



Specialized appendages in fuxianhuiids and the head organization of early euarthropods

The presence of a pair of specialized post-antennal appendages (SPAs) in the fuxianhuiid head, which attach at either side of the posteriorly directed mouth, behind the hypostome, indicates that antenniform deutocerebral appendages with many podomeres are a plesiomorphic feature of the ancestral euarthropod head.

Fossils from South China redefine the ancestral euarthropod body plan

Sklerolibyon and other jianfengiids expand the disparity of megacheirans and suggest that the common euarthropod ancestor possessed a remarkable phenotypic variability associated with the externalized cephalon, as well as endopods that were already heptopodomerous, which differs from previous hypotheses and observations.

Early fossil record of Euarthropoda and the Cambrian Explosion

While each of the major types of fossil evidence have their limitations and are incomplete in different ways, when taken together they allow a coherent picture to emerge of the origin and subsequent radiation of total group Euarthropoda during the Cambrian.

A middle Cambrian arthropod with chelicerae and proto-book gills

Fossil material from the middle Cambrian Burgess Shale is used to show that Mollisonia plenovenatrix possessed robust but short chelicerae that were placed very anteriorly, between the eyes, which suggests that chelicers evolved a specialized feeding function early on, possibly as a modification of short antennules.

A predatory bivalved euarthropod from the Cambrian (Stage 3) Xiaoshiba Lagerstätte, South China

The discovery of a new bivalved euarthropod from the Cambrian Hongjingshao Formation in Kunming, southern China offers novel insights on the morphology of the enigmatic genus Clypecaris, and indicates that the possession of paired dorsal spines is a diagnostic trait of the Family ClyPEcarididae within upper stem-group EUarthropoda.

New radiodonts with gnathobase‐like structures from the Cambrian Chengjiang biota and implications for the systematics of Radiodonta

Appraisal of available evidence indicates that the morphology of the feeding structures, including frontal appendages, the mouth apparatus, and GLSs, serves as a fundamental source of characters in the classification of radiodonts.

Cephalic and Limb Anatomy of a New Isoxyid from the Burgess Shale and the Role of “Stem Bivalved Arthropods” in the Disparity of the Frontalmost Appendage

The diversity of frontalmost appendages in “stem bivalved” arthropods, distinct in its absence of clear clustering, is found to link the morphologies of “short great appendages,” chelicerae and antennules, and fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods.

Burgess Shale fossils illustrate the origin of the mandibulate body plan

The presence of crustaceomorph traits in the Cambrian larvae of various clades basal to Mandibulata is reinterpreted as evidence for the existence of distinct ontogenetic niches among stem arthropods and Hymenocarines now illustrate that the subdivision of the basipod and the presence of proximal endites are likely to have been ancestral conditions critical for the evolution of coxal and pre-coxal features in mandibulates.