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Phragmactis

- Phragmactinidae

Taxonomy
Phragmactis was named by Spencer (1940) [Sepkoski's age data: O Ashg-m Sepkoski's reference number: 2]. It is not extant. It is the type genus of Phragmactidae.

It was assigned to Phragmactidae by Spencer (1951) and Owen (1965); to Stenurida by Sepkoski (2002); to Asterozoa by Spencer (1940) and Dean Shackleton (2005); and to Phragmactinidae by Spencer and Wright (1966) and Blake (2014).

Synonymy list
YearName and author
1940Phragmactis Spencer
1951Phragmactis Spencer p. 111
1965Phragmactis Owen p. 547
1966Phragmactis Spencer and Wright p. U81
2002Phragmactis Sepkoski, Jr.
2005Phragmactis Dean Shackleton p. 60
2014Phragmactis Blake p. 1164

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Nephrozoa
Deuterostomia
Ambulacraria
RankNameAuthor
phylumEchinodermata
subphylumAsterozoa
familyPhragmactinidae()
genusPhragmactis

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Diagnosis
ReferenceDiagnosis
J. Dean Shackleton 2005Madreporite contacting inferomarginal ossicle; loss of aboral plating; axillary oval in shape.
D. B. Blake 2014Phragmactinid lacking body-wall ossicles dorsal to marginals. Marginals in single series, their form shield-like. Axillary ventral, large, shield-like. Madreporite ventral in position but dorsal to marginal-axillary series. Podial pores lacking throughout arm length. Adambulacral forming an abradial rim to the ambulacral podial basin; adambulacrals broadest distally where abutting ambulacral transverse ridge, narrowing proximally. Ventral edge of MAO pair narrow, forming a possibly spine-bearing ridge.