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Odontochitina camura
Holotype. Plate 3, figure 14; GSCA slide no. P51205-05 (¼GSCC slide no. P5205–98H); coordinates 6.5x95.3; EF V51/4; Nunavut Palaeontology Collection no. NUPB 1005; Q section, Twosnout creek, Bylot Island. Bylot Island formation.
Etymology. The epithet is from the Latin camura, meaning turned inward or crooked, in reference to the way the lateral horn curves inward towards the antapical horn.
Diagnosis. A species of Odontochitina in which the shape of the endocyst less the operculum is angular, with the posterior margin being almost perpendicular to the vertical axis. Walls closely appressed except in the vicinity of the horns. Endophragm thicker than periphragm. The pericystal hypocyst bears a lateral (postcingular) horn and a dorsal (antapical) horn. Orientation of the postcingular horn is unusual in that it curves inwards towards the antapical horn, sometimes overlapping the latter. The antapical horn tends to be straight. Both the postcingular and antapical pericystal horns are slender, tapering to an acuminate distal termination. Traces of paratabulation occur on some specimens. A complete specimen with an apical horn was not observed.
Comments. An intriguing aspect of Odontochitina camura is the unusual relationship of the postcingular and antapical horns, with the former strongly curving towards and almost touching the latter in some specimens. Other species of Odontochitina showing unusually oriented lateral and antapical horns are Odontochitina diducta and Odontochitina dilatata, but in these species the two horns are splayed out to strongly divergent. Odontochitina camura is also distinctive in that the posterior margins of the endocyst and pericyst tend to be perpendicular to the longitudinal axis of the specimen. Odontochitina streelii differs in expressing paratabulation and divergent lateral and antapical horns.
Size. Holotype: overall length (excluding apical operculum and apical horn) 88um, pericyst length 45um, pericyst width 57um, endocyst length 45um, endocyst width 53um, lateral horn length 55um, lateral horn width proximally 10um and distally 1um, antapical horn length 41um, antapical horn width proximally 10um and distally 2um. Range of four specimens: overall length (excluding operculum) 41–88um, overall width (excluding lateral horn) 45–58um, pericyst length 42–53um, pericyst width 44–57um, lateral horn length 47–55um; lateral horn width proximally 5–11um and distally 1–2um, antapical horn length 39– 58um, antapical horn width proximally 8–12um and distally 1–2um.
Age. Campanian.
Etymology. The epithet is from the Latin camura, meaning turned inward or crooked, in reference to the way the lateral horn curves inward towards the antapical horn.
Diagnosis. A species of Odontochitina in which the shape of the endocyst less the operculum is angular, with the posterior margin being almost perpendicular to the vertical axis. Walls closely appressed except in the vicinity of the horns. Endophragm thicker than periphragm. The pericystal hypocyst bears a lateral (postcingular) horn and a dorsal (antapical) horn. Orientation of the postcingular horn is unusual in that it curves inwards towards the antapical horn, sometimes overlapping the latter. The antapical horn tends to be straight. Both the postcingular and antapical pericystal horns are slender, tapering to an acuminate distal termination. Traces of paratabulation occur on some specimens. A complete specimen with an apical horn was not observed.
Comments. An intriguing aspect of Odontochitina camura is the unusual relationship of the postcingular and antapical horns, with the former strongly curving towards and almost touching the latter in some specimens. Other species of Odontochitina showing unusually oriented lateral and antapical horns are Odontochitina diducta and Odontochitina dilatata, but in these species the two horns are splayed out to strongly divergent. Odontochitina camura is also distinctive in that the posterior margins of the endocyst and pericyst tend to be perpendicular to the longitudinal axis of the specimen. Odontochitina streelii differs in expressing paratabulation and divergent lateral and antapical horns.
Size. Holotype: overall length (excluding apical operculum and apical horn) 88um, pericyst length 45um, pericyst width 57um, endocyst length 45um, endocyst width 53um, lateral horn length 55um, lateral horn width proximally 10um and distally 1um, antapical horn length 41um, antapical horn width proximally 10um and distally 2um. Range of four specimens: overall length (excluding operculum) 41–88um, overall width (excluding lateral horn) 45–58um, pericyst length 42–53um, pericyst width 44–57um, lateral horn length 47–55um; lateral horn width proximally 5–11um and distally 1–2um, antapical horn length 39– 58um, antapical horn width proximally 8–12um and distally 1–2um.
Age. Campanian.