Oxynoticeratidae

Oxynoticeratidae is a family of true ammonites (order Ammonitida) included in the superfamily Psiloceratoidea.

Oxynoticeratidae
Temporal range: Early Jurassic, 196.5–186.7 Ma [1]
Fossil of Gleviceras guabalianum from France, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: †Ammonoidea
Order: †Ammonitida
Suborder: †Ammonitina
Superfamily: †Psiloceratoidea
Family: †Oxynoticeratidae
Hyatt, 1875

Oxynoticeratids have a broad, worldwide distribution but a narrow stratigraphic one, being known only from the Upper Sinemurian and Lower Pliensbachian,[2][3] during which their shells changed little in form.

Genera

[1]

Description

These cephalopds, as the other species in the superfamily Psiloceratoidea, are usually characterized by mostly involute, oxyconic shells with narrow venter and compressed, lanceolate whorl section. The suture line is of ammonitic type. Ribbing is feeble, hardly functional and often absent.

They have developed shorter body chambers than in the ancestral Arietitidae,[2] resulting in more stable floating positions. Their mostly smooth, knife-edge discoidal forms would have allowed for quick, though probably no sustained, movement through the water.

Distribution

Fossils of species within this genus have been found in the Jurassic sediments of Argentina, Canada, China, France, Hungary, Italy, Mexico, Morocco, Spain, Turkey and United Kingdom.[1]

gollark: Well, yes, but it blocks BlahOS.
gollark: ```lua-- Ensure code does not contain evil/unsafe things, such as known browsers, bad OSes or Siri. For further information on what to do if Siri is detected please consult https://pastebin.com/RM13UGFa line 2 and/or the documentation for PS#ABB85797 in this file.function potatOS.check_safe(code) local lcode = strip_comments(string.lower(code)) for category, list in pairs(banned) do for _, thing in pairs(list) do if string.find(lcode, '[^"]' .. string.lower(thing)) then --local ok, err = pcall(potatOS.make_paste, ("potatOS_code_sample_%x"):format(0, 2^24), code) --local sample = "[error]" --if ok then sample = "https://pastebin.com/" .. err end local text = string.format([[This program contains "%s" and will not be run.Classified as: %s.%sIf you believe this to be in error, please contact the potatOS developers.This incident has been reported.]], thing, category, category_descriptions[category]) potatOS.report_incident(string.format("use of banned program classified %s (contains %s).", category, thing), {"safety_checker"}, { code = code, extra_meta = { program_category = category, program_contains = thing, program_category_description = category_descriptions[category] } }) return false, function() printError(text) end end end end return trueend```
gollark: There's a bit of code in `load` which checks user code for stuff which looks like known virii/bad OSes.
gollark: I may need to improve the potatOS antivirus.
gollark: I've not *heard* of one.

References
  1. The Paleobiology Database
  2. Ammonites.fr
  3. Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopoda
  • Arkell et al., 1957. Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, pp. L240-L243. Geological Soc. of America and Univ. Kansas Press.
  • Donovan & Callomon, 1981. Ammonoidea.
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