New eocrinoids from the Burgess Shale, southern British Columbia, Canada, and the Spence Shale, northern Utah, USA

2006 ◽  
Vol 43 (3) ◽  
pp. 303-322 ◽  
Author(s):  
James Sprinkle ◽  
Desmond Collins

The family Lyracystidae n.fam. and genus Lyracystis n.gen. are proposed for the holotype and one paratype of the Middle Cambrian eocrinoid Gogia? radiata Sprinkle, the Burgess Shale "Arms" from the same unit, and many additional partial and more complete specimens of this eocrinoid collected from the Burgess Shale since 1975. A second species, Lyracystis reesei n.gen. and n.sp. is described from a single partly complete specimen from the similar-aged Spence Shale of northern Utah. Lyracystis has three wide V-shaped arms bearing numerous long straight brachioles in the notch, a partly organized theca having larger and smaller ridged plates with epispires, and a very long multiplated stalk made up of rounded or spiny small plates. Lyracystis is the longest-stalked, suspension-feeding echinoderm known from the Middle Cambrian. The three remaining paratypes of Gogia? radiata and four new specimens with possible branched brachioles from the Burgess Shale are renamed Gogia stephenensis n.sp.

2018 ◽  
Vol 33 (1) ◽  
pp. 83
Author(s):  
Rodolfo Gozalo ◽  
Mª Eugenia Dies-Álvarez ◽  
José Antonio Gámez VIintaned ◽  
Juan B. Chirivella ◽  
Eladio Liñan

 The genus Naraoia Walcott, 1912, a Burgess Shale-type fossil known from the lower and middle Cambrian of British Columbia (Canada), Idaho and Utah (USA), as well as from Yunnan and Guizhou provinces (China), is now reported from the middle Cambrian of Murero (Zaragoza, Spain), which is the first record in the Acadobaltic province. The only fragmented specimen found is determined as Naraoia sp., its age being Pardailhania multispinosa Zone (Drumian Stage). This new datum reinforces the hypothesis of the existence of a cosmopolitan faunal substrate in early Cambrian times, which is to some extent refl ected in the mid Cambrian by faunal groups of low evolutionary potential as the family Naraoiidae and other soft-bodied fossil taxa.


This, the first detailed description, interpretation and reconstruction of Odaraia alata , is based on all 29 known specimens. These include material of Eurysaces pielus Simonetta and Delle Cave, 1975, which is synonymized with O. alata herein. The head bore a pair of large eyes anteriorly and a paired mandible posteriorly. Features between these are poorly defined and the number of limb-bearing cephalic somites is unknown. The carapace was bivalved and essentially tubular in configuration, enclosing most of the body anteriorly. The trunk included up to at least 45 uniform short wide limb-bearing somites. The trunk appendages were biramous (with the possible exception of the first two), with an outer lamellate branch projecting dorsad of a segmented, spinose and apparently sometimes bifurcate inner branch which shows some evidence of variation along the trunk. The telson bore three large flukes, two projecting laterally and one vertically. The evidence suggests that O. alata fed by employing the carapace as a filter chamber within which the appendages, which trapped small pelagic animals, were confined. The arthropod probably swam on its back, using the appendages. Although the flukes did not articulate proximally, the telson appears to have been well adapted as a stabilizing and steering organ. O. alata shows some similarities to the Crustacea, particularly the Branchiopoda, but the preservation of the features of the cephalon is inadequate to allow its affinities to be determined unequivocally. It is classified in the family Odaraidae Simonetta and Delle Cave, 1975, but assignment to a higher taxon within the arthropods is not considered to be justified.


1996 ◽  
Vol 70 (2) ◽  
pp. 280-293 ◽  
Author(s):  
Desmond Collins

The remarkable “evolution” of the reconstructions of Anomalocaris, the extraordinary predator from the 515 million year old Middle Cambrian Burgess Shale of British Columbia, reflects the dramatic changes in our interpretation of early animal life on Earth over the past 100 years. Beginning in 1892 with a claw identified as the abdomen and tail of a phyllocarid crustacean, parts of Anomalocaris have been described variously as a jellyfish, a sea-cucumber, a polychaete worm, a composite of a jellyfish and sponge, or have been attached to other arthropods as appendages. Charles D. Walcott collected complete specimens of Anomalocaris nathorsti between 1911 and 1917, and a Geological Survey of Canada party collected an almost complete specimen of Anomalocaris canadensis in 1966 or 1967, but neither species was adequately described until 1985. At that time they were interpreted by Whittington and Briggs to be representatives of “a hitherto unknown phylum.”Here, using recently collected specimens, the two species are newly reconstructed and described in the genera Anomalocaris and Laggania, and interpreted to be members of an extinct arthropod class, Dinocarida, and order Radiodonta, new to science. The long history of inaccurate reconstruction and mistaken identification of Anomalocaris and Laggania exemplifies our great difficulty in visualizing and classifying, from fossil remains, the many Cambrian animals with no apparent living descendants.


2009 ◽  
Vol 277 (1-2) ◽  
pp. 86-105 ◽  
Author(s):  
Paul A. Johnston ◽  
Kimberley J. Johnston ◽  
Christopher J. Collom ◽  
Wayne G. Powell ◽  
Robyn J. Pollock

Old and new specimens of Sidneyia inexpectans have been studied and are accompanied by explanatory drawings and photographs. New reconstructions of the animal are given together with a three-dimensional model. The body consisted of a cephalon with a long backwardly directed doublure, a thorax of nine articulating somites, abdomen with cylindrical exoskeleton of two or three somites and a telson. A caudal fan was formed by a pair of uropods articulating at the posterior margin of the last abdominal somite. The cephalon had stalked eyes and preoral antennae but no walking or grasping appendages. The first four somites of the thorax had paired uniramous, prehensile walking legs attached to the body by broad coxae with spiny gnathobases. The coxae were smaller on the five posterior thoracic somites and the paired appendages were biramous, each bearing a gill supported on a flap attached at its proximal end to the first podomere of the leg. The coxa-body attachment resembles that of modern merostomes and is in advance of trilobites. Evidence suggests that Sidneyia was a bottom-living, carnivorous animal eating larger and harder food than trilobites. Gut contents include ostracodes, hyolithids, small trilobites and phosphatic debris. Sidneyia is the earliest known form which could be an ancestor to merostomes, but its body plan and absence of chelicera distinguishes Sidneyia from this group. The holotype of Amiella ornata Walcott, 1911 is reinterpreted and its synonomy with S. inexpectans is confirmed.


2015 ◽  
Vol 370 (1666) ◽  
pp. 20140313 ◽  
Author(s):  
Derek E. G. Briggs

Harry Whittington's 1975 monograph on Opabinia was the first to highlight how some of the Burgess Shale animals differ markedly from those that populate today's oceans. Categorized by Stephen J. Gould as a ‘weird wonder’ ( Wonderful life , 1989) Opabinia , together with other unusual Burgess Shale fossils, stimulated ongoing debates about the early evolution of the major animal groups and the nature of the Cambrian explosion. The subsequent discovery of a number of other exceptionally preserved fossil faunas of Cambrian and early Ordovician age has significantly augmented the information available on this critical interval in the history of life. Although Opabinia initially defied assignment to any group of modern animals, it is now interpreted as lying below anomalocaridids on the stem leading to the living arthropods. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society .


Sign in / Sign up

Export Citation Format

Share Document