Erikaspis sp.
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publication ID |
https://doi.org/ 10.4202/app.00395.2017 |
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persistent identifier |
https://treatment.plazi.org/id/566487BD-1673-FFBD-AAAD-FA0EFE24FE99 |
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treatment provided by |
Felipe |
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scientific name |
Erikaspis sp. |
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Fig. 3B, D, F View Fig .
Material.—Muz PGI 1733.II.183 ( Fig. 3D View Fig ), Muz PGI 1733. II.383 ( Fig. 3G View Fig ), MZ-VIII/Vp-480 ( Fig. 3B View Fig ), anterior lateral plates; Podłazie hill, Lower Devonian, Emsian.
Description.— Anterior lateral plates: MZ-VIII/Vp-480 corresponds to the upper part of right plate ( Fig. 3G View Fig ), Muz PGI 1733.II.183, the completely preserved left plate ( Fig. 3D View Fig ), and Muz PGI 1733.II.383, the partially preserved right plate with its upper margin broken ( Fig. 3G View Fig ). The shape of the former two allows to determine the typical trapezoidal outline with straight slightly rounded and undulating boundary contacting the posterolateral and posterodorsolateral plates. The anteroventral margin is straight and narrow. All specimens appear to be similar in size. Tubercles (up to 1.5 mm in diametre) form oblique rows that radiate from the growth center to the angles of the plate which happens to be located close to the posteroventral corner of the plate ( Fig. 3D, G View Fig ). In the posterior part a pectoral notch is clearly visible as a shallow embayment.
Remarks.—Within anterior lateral plates the specimen MZ-VIII/Vp-480 ( Fig. 3B View Fig ) reflects some characteristics similar to those observed in Kujdanowiaspis podolica . These are: dorsal quadrant and postero-dorsal angle forming a rounded lobe. It resembles the right anterolateral plate of K. podolica illustrated by Dupret (2010: fig. 20B) and that of Aleosteus eganensis ( Johnson et al. 2000: fig. 2J). Muz PGI 1733. II.183 and Muz PGI 1733.II.383 ( Fig. 3D, G View Fig ) are characterised by straighter margins, but they fit roughly to the morphology of the K. podolica plates ( Dupret 2010: fig. 20A, B). The difference lays in the absence of crests and quadrant in specimen Muz PGI 1733.II.183 ( Fig. 3D View Fig ). Moreover, the ornamentation is extremelly similar to that observed in Erikaspis zychi , although the shape of the plate in this latter form is higher than long and resembles more that observed in Actinolepis magna ( Dupret et al. 2007) . It would be possible to consider that the square shape of the anterior lateral plate in Erikaspis is a juvenile character, and that the plate becomes higher as the animal get older. For this taxonomic determination, we put more weight on the ornamentation than on the shape of the plate.
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