Sphaerophthalmus Angelin, 1854

Ahlberg, Per, Szaniawski, Hubert, Clarkson, Euan N. K. & Bengtson, Stefan, 2005, Phosphatised olenid trilobites and associated fauna from the Upper Cambrian of Västergötland, Sweden, Acta Palaeontologica Polonica 50 (3), pp. 429-440 : 431-433

publication ID

https://doi.org/ 10.5281/zenodo.13620385

persistent identifier

https://treatment.plazi.org/id/315A9976-FFA4-FFEE-FCD6-5860FE98FC7D

treatment provided by

Felipe

scientific name

Sphaerophthalmus Angelin, 1854
status

 

Genus Sphaerophthalmus Angelin, 1854 View in CoL Sphaerophthalmus humilis ( Phillips, 1848)

Fig. 2I–K View Fig .

Olenus humilis n. sp.; Phillips 1848: 55, 347, figs. 4–6. Sphaerophthalmus humilis ( Phillips, 1848) View in CoL ; Żylińska 2001: 344, pl. 2:

1a, pl. 3: 2–3 [see for complete synonymy].

Material.—Two cranidia and three pygidia.

Description.—The two cranidia are 0.8 and 1.3 mm long, respectively. The smaller one ( Fig. 2I View Fig ) is almost complete except for the occipital ring. The specimens agree in most respects with Henningsmoen´s (1957) description of the species. The palpebral lobes are very narrow, becoming wider anteriorly, with their centres situated on a transverse line slightly in front of S1. A tiny intergenal spine is present on the rounded postero−lateral margin. The surface is very finely granulated.

The three pygidia (0.7, 0.8, and 0.9 mm long) can confidently be assigned to the species. They are triangular in shape with nearly straight and slightly undulating postero−lateral margins. The axis is very broad, anteriorly occupying six−tenths of the total width, and tapers backwards almost to the tip of the pygidium. It consists of a prominent articulating half−ring, three axial rings, and a terminal piece. The pleural fields are very narrow and there is a distinct, raised postero−lateral border with two, possibly three, elongated lobes opposite the axial rings, arranged parallel to the margin. The surface of the pygidium is covered with granules except on the articulating half−ring. These are most prominent on the central part of the axial rings and behind the axis. On the pleural fields the granules are more elongated, subparallel with the postero−lateral margin. Terrace lines are present on the postero−lateral borders, being especially well developed on the most anterior lobes.

Kingdom

Animalia

Phylum

Arthropoda

Class

Trilobita

Order

Ptychopariida

Family

Olenidae

Loc

Sphaerophthalmus Angelin, 1854

Ahlberg, Per, Szaniawski, Hubert, Clarkson, Euan N. K. & Bengtson, Stefan 2005
2005
Loc

Olenus humilis

Zylinska, A. 2001: 344
Phillips, J. 1848: 55
1848
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