Ananaspis Campbell, 1967

Sandford, Andrew C. & Holloway, David J., 2006, Early Silurian phacopide trilobites from central Victoria, Australia, Memoirs of Museum Victoria 63 (2), pp. 215-255 : 223-224

publication ID

https://doi.org/ 10.24199/j.mmv.2006.63.17

persistent identifier

https://treatment.plazi.org/id/9C6887D7-FF81-3F0B-6525-F92FABA3F8FD

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Felipe

scientific name

Ananaspis Campbell, 1967
status

 

Ananaspis Campbell, 1967

Type species. Phacops fecundus Barrande, 1846 from the Kopanina Formation (Ludlow), Koledník, Bohemia, by original designation .

Diagnosis. Glabella moderately to strongly convex (sag., tr.), vertical or slightly overhanging anteriorly in dorsal view. Composite lobe expanding strongly forward, maximum width twice width at L1 or a little more. L2 commonly significantly shorter (exsag.) than L3. Eye of moderate to large size, lower edge situated in or slightly above lateral border furrow anteriorly and distant from lateral border furrow posteriorly, visual surface lacking strongly raised sclera (may be slightly thickened dorsally). Palpebral area as high as or higher than palpebral lobe. Fixigenal portion of lateral border furrow deep and continuous with posterior border furrow. Vincular furrow shallow to moderately impressed medially, commonly rather weakly notched laterally. Glabellar sculpture of bimodal tubercles lacking perforations and with superimposed and interspersed granules, doublure finely and densely granulate. Hypostome with short (sag.) posterior border having 3 angular points on margin. Pygidial pleural furrows deep and wide (exsag.), interpleural furrows distinct.

Remarks. This diagnosis distinguishes Ananaspis from a number of closely related genera recognised since the work of Campbell (1967). Echidnops Sandford, 2002 is the closest to Ananaspis but differs not only in having characteristic occipital and thoracic axial spines but also a much more deeply incised vincular furrow medially. Paciphacops Maksimova, 1972 is distinguished especially by the strongly raised sclera on the visual surface and the perforate glabellar tubercles, but in addition L1 is more depressed medially, the glabella is more raised and subquadrate in anterior profile, and the vincular furrow is deep medially. Lochkovella Chlupáč, 1972 (see also Sandford, 2004) differs from Ananaspis in that the cephalic tuberculation is finer and of more uniform size, the eye is situated very low on the cheek with its lower edge indenting the lateral cephalic border, the hypostome has a long (sag.) posterior border with five marginal denticles, the pygidial interpleural furrows are not as deep, and the pygidial granulation is coarser. Similar distinctions can be made with Nephranomma Erben, 1952 (see Sandford, 2003) which further differs from Ananaspis in lacking a vincular furrow medially and in having a distinctive scaly sculpture on the cephalic doublure. See the remarks on Ivops gen. nov. for comparison of that genus with Ananaspis .

Kingdom

Animalia

Phylum

Arthropoda

Class

Trilobita

Order

Phacopida

Family

Phacopidae

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