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Temporal range: Darriwilian [1] -Silurian
FMIB 46280 Ceratiocaris papilio, one of the fossil Phyllocarda.jpeg
Scientific classification

M'Coy, 1849
Type species
Ceratiocaris solenoides
M'Coy, 1849

Ceratiocaris is a genus of paleozoic phyllocarid crustaceans whose fossils are found in marine strata from the Upper Ordovician until the genus' extinction during the Silurian. They are typified by eight short thoracic segments, seven longer abdominal somites and an elongated pretelson somite. Their carapace is slightly oval shaped; they have many ridges parallel to the ventral margin and possess a horn at the anterior end. [2] They are well known from the Silurian Eramosa formation of Ontario, Canada. [3] [4]

The following species are included:

Related Research Articles

<i>Waptia</i> Species of crustacean (fossil)

Waptia fieldensis is an extinct species of arthropod from the Middle Cambrian Burgess Shale Lagerstätte of Canada. It grew to a length of about 8 cm (3 in) and resembled modern shrimp in both morphology and habit. It had a large bivalved carapace and a segmented body terminating into a pair of tail flaps. It was an active swimmer, feeding on organic particles it gathered from the seafloor substrate. It is also one of the oldest animals with direct evidence of brood care.

Chaetocladus is a non-calcifying genus of unicellular green algae known from the Upper Silurian.


Chasmataspidids, sometime referred to as chasmataspids, are a group of extinct chelicerate arthropods that form the order Chasmataspidida. Chasmataspidids are probably related to horseshoe crabs (Xiphosura) and/or sea scorpions (Eurypterida), with more recent studies suggest that they form a clade (Dekatriata) with Eurypterida and Arachnida. Chasmataspidids are known sporadically in the fossil record through to the mid-Devonian, with possible evidence suggesting that they were also present during the late Cambrian. Chasmataspidids are most easily recognised by having an opisthosoma divided into a wide forepart (preabdomen) and a narrow hindpart (postabdomen) each comprising 4 and 9 segments respectively. There is some debate about whether they form a natural group.


Acutiramus is a genus of giant predatory eurypterid, an extinct group of aquatic arthropods. Fossils of Acutiramus have been discovered in deposits of Late Silurian to Early Devonian age. Seven species have been described, five from North America and two from the Czech Republic. The generic name derives from Latin acuto and Latin ramus ("branch"), referring to the acute angle of the final tooth of the claws relative to the rest of the claw.


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The Eramosa is a Silurian stratigraphic unit exposed along the Niagara Escarpment in Ontario and western New York State. In the late nineteenth century it was an important source of building stone in Hamilton, Ancaster and Waterdown, and in the late twentieth century quarries in a similar unit, also called the Eramosa, near Wiarton in the Bruce Peninsula, became an important source of dimension stone at a time when most of the other resources of similar stone were depleted. Work in these quarries led to the discovery of exceptionally well preserved fossils. On the east Mountain at Hamilton, a well-developed cave system was discovered in the Eramosa and has now been designated as the Eramosa Karst Conservation Area.

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Synziphosurina Group of arthropods

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Paleontology in Wisconsin

Paleontology in Wisconsin refers to paleontological research occurring within or conducted by people from the U.S. state of Wisconsin. The state has fossils from the Precambrian, much of the Paleozoic, and the later part of the Cenozoic. Most of the Paleozoic rocks are marine in origin. Because of the thick blanket of Pleistocene glacial sediment that covers the rock strata in most of the state, Wisconsin’s fossil record is relatively sparse. In spite of this, certain Wisconsin paleontological occurrences provide exceptional insights concerning the history and diversity of life on Earth.


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Timeline of eurypterid research

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The Waukesha Biota refers to the biotic assemblage of the Konservat-Lagerstätte of Early Silurian age within the Brandon Bridge Formation in Waukesha County and Franklin, Milwaukee County, Wisconsin. It is known for the exceptional preservation of its diverse, soft-bodied and lightly skeletonized taxa, including many major taxa found nowhere else in strata of similar age.

<i>Venustulus</i> Extinct genus of chelicerate

Venustulus is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Venustulus was regarded as part of the clade Prosomapoda. Fossils of the single and type species, V. waukeshaensis, have been discovered in deposits of the Silurian period in Wisconsin, in the United States. Venustulus is one of the few synziphosurine genera with fossil showing evidence of appendages.

<i>Camanchia</i> Extinct genus of chelicerate

Camanchia is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Camanchia was regarded as part of the clade Prosomapoda. Fossils of the single and type species, C. grovensis, have been discovered in deposits of the Silurian period in Iowa, in the United States. Alongside Venustulus, Camanchia is one of the only Silurian synziphosurine with fossil showing evidence of appendages.


  1. 1 2 Derek E.G. Briggs; Huaibao P. Liu; Robert M. McKay; Brian J. Witzke (2016). "Bivalved arthropods from the Middle Ordovician Winneshiek Lagerstätte, Iowa, USA". Journal of Paleontology. 89 (6): 991–1006. doi:10.1017/jpa.2015.76.
  2. Joseph H. Collette; David M. Rudkin (2010). "Phyllocarid crustaceans from the Silurian Eramosa Lagerstätte (Ontario, Canada): taxonomy and functional morphology". Journal of Paleontology . 84 (1): 118–127. doi:10.1666/08-174.1.
  3. J. H. Collette; J. W. Hagadorn (2010). "Early evolution of phyllocarid arthropods: phylogeny and systematics of Cambrian-Devonian archaeostracans". Journal of Paleontology . 84 (5): 795–820. doi:10.1666/09-092.1.
  4. M. Copeland; T. E. Bolton (1985). Fossils of Ontario part 3: the eurypterids and phyllocarids . Life Sciences Miscellaneous Publications. Volume 48. Royal Ontario Museum. ISBN   0-88854-314-X.