PBDB Taxon

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Ptychoparella

Trilobita - Ptychopariida - Ptychopariidae

Taxonomy

Ptychoparella was named by Poulson (1927) [Sepkoski's age data: Cm Tojo-u Sepkoski's reference number: 497]. It is not extant. It is the type genus of Ptychopariidae.

It was assigned to Ptychopariidae by Jell and Adrain (2002); and to Ptychopariida by Sepkoski (2002).

Species

Elrathina antiqua, Elrathina cordillerae, Elrathina marginalis, Elrathina offula, Elrathina wheelera, P. minuta, P. usualis, Syspacephalus cadyi, Syspacephalus charops, Syspacephalus crassus, Syspacephalus gregarius, Syspacephalus laticeps, Syspacephalus longus, Syspacephalus mccollumorum, Syspacephalus vapidus, Syspacephalus variosus, Syspacephalus werneckensis

Species lacking formal opinion data

P. kindlei

Synonyms

Elrathina was named by Resser (1937) [Sepkoski's age data: Cm lMid Cm uMid-l Sepkoski's reference number: 81,379]. It is not extant.

It was synonymized subjectively with Ptychoparella by Jell and Adrain (2002).

It was assigned to Ptychopariina by Sundberg (1994); to Ptychopariida by Palmer and Halley (1979) and Sepkoski (2002); and to Arthropoda by Caron and Jackson (2008).
Syspacephalus was named by Resser (1936) [Sepkoski's age data: Cm Tojo-l Cm lMid Sepkoski's reference number: 81,475].

It was synonymized subjectively with Ptychoparella by Jell and Adrain (2002).

It was assigned to Corynexochidae by Resser (1936); and to Ptychopariida by Palmer and Halley (1979) and Sepkoski (2002).

Synonymy list

Year	Name and author
1927	Ptychoparella Poulson
1936	Syspacephalus Resser p. 28
1937	Elrathina Resser
1979	Elrathina Palmer and Halley p. 103
1979	Syspacephalus Palmer and Halley p. 115
1994	Elrathina Sundberg p. 109
2002	Ptychoparella Jell and Adrain p. 436
2002	Elrathina Sepkoski
2002	Ptychoparella Sepkoski
2002	Syspacephalus Sepkoski
2008	Elrathina Caron and Jackson p. 226

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Protostomia
—	Ecdysozoa
—	Panarthropoda
phylum	Arthropoda	Latreille 1829

Rank	Name	Author
subphylum	Artiopoda	(Hou and Bergstrom)
class	Trilobita	Walch 1771
subclass	Libristoma
order	Ptychopariida	Swinnerton 1915
family	Ptychopariidae	Matthew 1887
genus	Ptychoparella	Poulson 1927

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.

G. †Ptychoparella Poulson 1927

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†Ptychoparella minuta Yang et al. 1993

†Ptychoparella usualis Chien and Zhou 1974

Invalid names: Elrathina Resser 1937 [synonym], Syspacephalus Resser 1936 [synonym]

Diagnosis

Reference	Diagnosis
C. E. Resser 1936 (Syspacephalus)	Small trilobites of which the cranidium alone is known. Glabella narrow, tapering slightly ; truncated, about two-thirds as long as cranidium ; in some species ill defined on upper surface of test. Glabellar furrows showing on inner side of test. Brim convex with faint frontal furrows extending inward from the anterior angles for varying distances. Facial suture converging anterior to eyes. Eyes small. Occipital furrow developed on the cheeks, but sometimes al- most obsolete on the cranidium.
F. A. Sundberg 1994 (Elrathina)	Small, micropygous Ptychopariida with subrectangular cranidium with convergent fa- cial sutures anterior of the palpebral lobes, glabella elevated above fixigena; parallel to slightly conver- gent, moderate depth axial furrows; shallow to ef- faced lateral glabellar furrows; strongly rounded frontal lobe; slightly downsloping, moderately wide fixigenae; narrow preglabellar field; convex, slightly to moderately curved, sagittally narrow, tapering anterior border; short palpebral lobes anterior of glabellar midlength. Free checks lack significant development of genal spines. Triangular pygidium.