As the largest predators of Cambrian seas, anomalocaridids had an important impact in structuring first complex marine animal communities, but many aspects anomalocaridid morphology, diversity, ecology, and affinity remain unclear owing to a paucity specimens. Here we describe Hurdia, based on several hundred specimens from Burgess Shale Canada. Hurdia possesses general body architecture similar those Anomalocaris Laggania, including presence exceptionally well-preserved gills, differs by...

Halkieriids and wiwaxiids are cosmopolitan sclerite-bearing metazoans from the Lower Middle Cambrian. Although they have similar scleritomes, their phylogenetic position is contested. A new scleritomous fossil Burgess Shale has prominent anterior shell of halkieriids but also bears wiwaxiid-like sclerites. This defines monophyletic halwaxiids indicates that a key place in early lophotrochozoan history.

Extant arthropods are diverse and ubiquitous, forming a major constituent of most modern ecosystems. Evidence from early Palaeozoic Konservat Lagerstätten indicates that this has been the case since Cambrian. Despite this, details arthropod origins remain obscure, although hypotheses regard first as benthic predators or scavengers such fuxianhuiids megacheirans (‘great-appendage’ arthropods). Here, we describe new Tulip Beds locality Burgess Shale Formation (Cambrian, series 3, stage 5)...

The Middle Cambrian Pikaia gracilens (Walcott) has an iconic position as a chordate, but until now no detailed description been available. Here on the basis of 114 available specimens we review its anatomy, confirm place in chordates and explore with varying degrees confidence relationships to both extant extinct other deuterostomes. body is fusiform, laterally compressed possesses about 100 myomeres. head small, bilobed bears two narrow tentacles. There evidence for eyes. Apart from thin...

In Cambrian fossil Lagerstätten like the Burgess Shale, exceptionally preserved arthropods constitute a large part of taxonomic diversity, providing opportunities to study early evolution this phylum in detail. The anomalocaridids, presumed pelagic predators, are particularly relevant owing their unique combination morphological characters and basal position arthropod stem lineage. Although isolated elements fragmented specimens were first discovered over 100 years ago, subsequent findings...

One of the first phyla to acquire biomineralized skeletal elements in Cambrian, brachiopods represent a vital component unraveling early evolution and relationships Lophotrochozoa. Critical improving our understanding lophotrochozoans is origin, function unbiomineralized morphological features, particular features such as chaetae that are shared between other but poorly understood rarely preserved. Micromitra burgessensis Paterina zenobia from middle Cambrian Burgess Shale among most...

Abstract The middle (Wuliuan Stage) Cambrian Burgess Shale is famous for its exceptional preservation of diverse and abundant soft-bodied animals through the “thick” Stephen Formation. However, with exception Walcott Quarry (Fossil Ridge) stratigraphically older Tulip Beds (Mount Stephen), which are both in Yoho National Park (British Columbia), quantitative assessments have remained limited. Here we first provide a detailed overview diversity structure Marble Canyon locality based on 16,438...

Waptia fieldensis Walcott, 1912 is one of the iconic animals from middle Cambrian Burgess Shale biota that had lacked a formal description since its discovery at beginning twentieth century. This study, based on over 1800 specimens, finds W. shares general characteristics with pancrustaceans, as previous authors suggested mostly overall aspect. The cephalothorax covered by flexible, bivalved carapace and houses pair long multisegmented antennules, palp-bearing mandibles, maxillules, four...

Radiodonts, a clade of Cambro-Devonian stem group euarthropods, have classically been regarded as nektonic apex predators. However, many aspects radiodont morphology and ecology remained unclear because the typically fragmentary nature fossil material. Here, we describe new hurdiid based on abundant exceptionally well-preserved fossils from Burgess Shale (Marble Canyon area, British Columbia, Canada). Cambroraster falcatus gen. et sp. nov . is characterized by an extra-large horseshoe-shaped...

Abstract The degree to which the original community composition of Middle Cambrian Burgess Shale was altered through transport and decay how taphonomic conditions varied time across taxa is poorly understood. To address these issues, variation in fossil preservation analyzed a vertical succession 26 bed assemblages, each representing single obrution event, within 7-m-thick Greater Phyllopod Bed Walcott Quarry. More than 50,000 specimens belonging 158 genera—mostly benthic, monospecific...

Research Article| September 01, 2010 A new Burgess Shale–type assemblage from the "thin" Stephen Formation of southern Canadian Rockies Jean-Bernard Caron; Caron 1Department Natural History-Palaeobiology, Royal Ontario Museum, 100 Queen's Park, Toronto, M5S 2C6, Canada Search for other works by this author on: GSW Google Scholar Robert R. Gaines; Gaines 2Pomona College, Geology Department, 185 E. Sixth Street, Claremont, California 91711, USA M. Gabriela Mángano; Mángano 3Department...

Molecular and morphological evidence unite the hemichordates echinoderms as Ambulacraria, but their earliest history remains almost entirely conjectural. This is on account of disparity ambulacrarians a paucity obvious stem-groups. We describe here new taxon Herpetogaster collinsi gen. et sp. nov. from Burgess Shale (Middle Cambrian) Lagerstätte. soft-bodied vermiform animal has pair elongate dendritic oral tentacles, flexible stolon with an attachment disc, re-curved trunk at least 13...

Lagerstätten from the Precambrian–Cambrian transition have traditionally been a relatively untapped resource for understanding paleoecology of “Cambrian explosion.” This quantitative paleoecological study is based on 10,238 fossil specimens belonging to 100 animal species, 11 phyla, and 15 ecological categories lower Cambrian (Series 2, Stage 3) Chengjiang biota (Mafang locality near Haikou, Yunnan Province, China). Fossils were systematically collected within 2.5-meter-thick sequence...