Topic
Haootia
About: Haootia is a research topic. Over the lifetime, 4 publications have been published within this topic receiving 111 citations.
Papers
TL;DR: Haootia quadriformis potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record.
Abstract: Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized muscular tissue before the Early Cambrian has hitherto remained moot, being reliant upon indirect evidence in the form of Late Ediacaran ichnofossils. We here report a candidate muscle-bearing organism, Haootia quadriformis n. gen., n. sp., from approximately 560 Ma strata in Newfoundland, Canada. This taxon exhibits sediment moulds of twisted, superimposed fibrous bundles arranged quadrilaterally, extending into four prominent bifurcating corner branches. Haootia is distinct from all previously published contemporaneous Ediacaran macrofossils in its symmetrically fibrous, rather than frondose, architecture. Its bundled fibres, morphology, and taphonomy compare well with the muscle fibres of fossil and extant Cnidaria, particularly the benthic Staurozoa. Haootia quadriformis thus potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record.
103 citations
1 Jan 2016
TL;DR: The strongest evidence of affinity with coronate scyphozoans is exhibited by Paraconularia sp.
Abstract: Recent molecular clock studies place the origin of phylum Cnidaria within the Cryogenian Period (ca. 850–635 Ma), with the split between the two subphyla (Anthozoaria and Medusozoa) likewise occurring during this time interval. However, the oldest cnidarian macrofossils, all medusozoans, occur in rocks of the late Ediacaran Period (ca. 560–541 Ma). Lightly skeletonized Corumbella werneri, currently known from late Ediacaran strata of Brazil, Paraguay and Nevada (USA), has been allied with coronate and conulariid scyphozoans, but it also shares gross morphological similarities with Carinachites spinatus, a possible conulariid from Cambrian Stage 1 (China), and it may be compared with Sinotubulites and Wutubus annularis from the late Ediacaran Dengying Formation (China). The strongest evidence of affinity with coronate scyphozoans is exhibited by Paraconularia sp. from a Corumbella-bearing shale interval in the latest Ediacaran Tamengo Formation of central Brazil. Furthermore, Paraconularia sp. from this rock unit establishes conulariids as a cnidarian clade that crossed the Proterozoic-Phanerozoic boundary. Finally, Haootia quadriformis from the late Ediacaran lower Fermeuse and Trepassy formations (southeastern Newfoundland, Canada) exhibits intriguing gross morphological similarities to extant staurozoans and may represent the earliest record of metazoan musculature. Together, C. werneri and latest Ediacaran Paraconularia sp. fix the split between the medusozoan classes Cubozoa and Scyphozoa at no later than ca. 543 Ma. If H. quadriformis was indeed a staurozoan or stem staurozoan, then this fossil taxon fixes the split between the class Staurozoa and all other medusozoan cnidarians at no later than ca. 560 Ma.
48 citations
TL;DR: Haootia quadriformis was described from the lower Fermeuse Formation of the Bonavista Peninsula of Newfoundland and its numerous regularly aligned impressions were interpreted as evidence of muscular tissue, resulting in the belief that this fossil could represent the fossilised remains of Tournaisia.
Abstract: Haootia quadriformis was described from the lower Fermeuse Formation of the Bonavista Peninsula of Newfoundland (approx. 560 Ma) and its numerous regularly aligned impressions were interpreted as evidence of muscular tissue ([[1][1], figs 1 a and 3 b ]). Consequently, this fossil could represent the
20 citations
TL;DR: Haootia quadriformis from Newfoundland, Canada, is one of the most unusual impressions of a soft-bodied macro-organism yet described from the late Ediacaran Period.
Abstract: Haootia quadriformis from Newfoundland, Canada, is one of the most unusual impressions of a soft-bodied macro-organism yet described from the late Ediacaran Period. Interpreted as a metazoan of cnidarian grade [[1][1]], the body impression of H. quadriformis possesses features interpreted as fibrous
13 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2016 | 1 |
| 2015 | 2 |
| 2014 | 1 |