scholarly journals A problematic animal fossil from the early Cambrian Hetang Formation, South China—A reply

2019 ◽  
Vol 93 (06) ◽  
pp. 1279-1282 ◽  
Author(s):  
Qing Tang ◽  
Jie Hu ◽  
Guwei Xie ◽  
Xunlai Yuan ◽  
Bin Wan ◽  
...  

AbstractWe recently reported Cambrowania ovata Tang and Xiao in Tang et al., 2019, from the early Cambrian Hetang Formation in South China and interpreted it as a problematic animal fossil, possibly related to either sponges or bivalved arthropods (Tang et al., 2019). Slater and Budd (2019) contested our taxonomic identification and phylogenetic interpretation; instead, they claimed that Cambrowania ovata is a large acritarch referable to morphotaxon Leiosphaeridia Eisenack, 1958, and thus is not an animal. Here we refute their criticisms, clarify the differences between Cambrowania and Leiosphaeridia and other acritarchs, and reiterate why an animal affinity for Cambrowania cannot be ruled out.

2010 ◽  
Vol 77 (1) ◽  
pp. 1-6 ◽  
Author(s):  
HAN Jian ◽  
ZHANG Xingliang ◽  
ZHANG Zhifei ◽  
SHU Degan

2019 ◽  
Vol 530 ◽  
pp. 281-299 ◽  
Author(s):  
Manabu Nishizawa ◽  
Yuki Tsuchiya ◽  
Wei Du ◽  
Yusuke Sawaki ◽  
Yohei Matsui ◽  
...  

2020 ◽  
Vol 117 ◽  
pp. 104355 ◽  
Author(s):  
Zhanghu Wang ◽  
Jingqiang Tan ◽  
Richard Boyle ◽  
Jason Hilton ◽  
Zhongliang Ma ◽  
...  

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Cédric Aria ◽  
Fangchen Zhao ◽  
Han Zeng ◽  
Jin Guo ◽  
Maoyan Zhu

Abstract Background Early Cambrian Lagerstätten from China have greatly enriched our perspective on the early evolution of animals, particularly arthropods. However, recent studies have shown that many of these early fossil arthropods were more derived than previously thought, casting uncertainty on the ancestral euarthropod body plan. In addition, evidence from fossilized neural tissues conflicts with external morphology, in particular regarding the homology of the frontalmost appendage. Results Here we redescribe the multisegmented megacheirans Fortiforceps and Jianfengia and describe Sklerolibyon maomima gen. et sp. nov., which we place in Jianfengiidae, fam. nov. (in Megacheira, emended). We find that jianfengiids show high morphological diversity among megacheirans, both in trunk ornamentation and head anatomy, which encompasses from 2 to 4 post-frontal appendage pairs. These taxa are also characterized by elongate podomeres likely forming seven-segmented endopods, which were misinterpreted in their original descriptions. Plesiomorphic traits also clarify their connection with more ancestral taxa. The structure and position of the “great appendages” relative to likely sensory antero-medial protrusions, as well as the presence of optic peduncles and sclerites, point to an overall homology with the anterior head of radiodontans. This is confirmed by our Bayesian phylogeny, which places jianfengiids as the basalmost euarthropods, paraphyletic with other megacheirans, and in contiguity with isoxyids and radiodontans. Conclusions 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. These animals also demonstrate that the frontalmost pair of arthrodized appendage is homologous between radiodontans and megacheirans, refuting the claim that the radiodontan frontal appendages evolved into the euarthropod labrum, and questioning its protocerebral identity. This evidence based on external anatomy now constitutes a solid benchmark upon which we should address issues of homology, with the help of carefully examined palaeoneurological data.


2015 ◽  
Vol 112 (28) ◽  
pp. 8678-8683 ◽  
Author(s):  
Jie Yang ◽  
Javier Ortega-Hernández ◽  
Sylvain Gerber ◽  
Nicholas J. Butterfield ◽  
Jin-bo Hou ◽  
...  

We describe Collinsium ciliosum from the early Cambrian Xiaoshiba Lagerstätte in South China, an armored lobopodian with a remarkable degree of limb differentiation including a pair of antenna-like appendages, six pairs of elongate setiferous limbs for suspension feeding, and nine pairs of clawed annulated legs with an anchoring function. Collinsium belongs to a highly derived clade of lobopodians within stem group Onychophora, distinguished by a substantial dorsal armature of supernumerary and biomineralized spines (Family Luolishaniidae). As demonstrated here, luolishaniids display the highest degree of limb specialization among Paleozoic lobopodians, constitute more than one-third of the overall morphological disparity of stem group Onychophora, and are substantially more disparate than crown group representatives. Despite having higher disparity and appendage complexity than other lobopodians and extant velvet worms, the specialized mode of life embodied by luolishaniids became extinct during the Early Paleozoic. Collinsium and other superarmored lobopodians exploited a unique paleoecological niche during the Cambrian explosion.


2008 ◽  
Vol 308 (4) ◽  
pp. 399-420 ◽  
Author(s):  
W. Compston ◽  
Z. Zhang ◽  
J. A. Cooper ◽  
G. Ma ◽  
R.J.F. Jenkins

2014 ◽  
Vol 25 (3) ◽  
pp. 1057-1069 ◽  
Author(s):  
Ryohei Kikumoto ◽  
Miyuki Tahata ◽  
Manabu Nishizawa ◽  
Yusuke Sawaki ◽  
Shigenori Maruyama ◽  
...  

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