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Helicoplacus (often
misspelled Helioplacus) is the
earliest well-studied
fossil echinoderm.
Fossil plates are
known from
several regions.
Complete specimens...
- †Helicoplacidae †
Helicoplacus Durham & Caster, 1963 †Polyplacus Durham, 1967 †Waucobella Durham, 1967
Helicoplacus guthi, one of two
species of
Helicoplacus, was...
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Helicoplacus† (a Helicoplacoid†)...
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Helicoplacus...
- 3 of the Cambrian, 521 million
years ago
starting with
forms such as
Helicoplacus. Two
other Cambrian Stage 3 (521-514 mya) species,
Haikouichthys and...
- not, in fact, be such structures. No
known orders, 2
known species,
Helicoplacus curtisi and H.
guthi Order Coronata †
Order Fissiculata †
Order Spiraculata...
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Helicoplacus...
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applegatei – type
locality for
species †Heintzella
playfordi †
Helicoplacus †
Helicoplacus gilberti †Helicoprion †Helicoprion
davisii †Helicotoma †Helicotoma...
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report †Euomphalus †Fallotaspis †Favosites †Fenestella †Gogia †Halysites †
Helicoplacus †Helicoprion †Helicoprion
davisii †Heliomeroides †Hercynella †Holopea...
- †Helfriedella †Helianthaster †Heliaster †Helicocrinus †Helicocystis †
Helicoplacus †Heliocidaris †Heliocrinites †Heliophora †Heliosocrinus †Helodiadema...
