Basseiarges

Order:  LICHIDA  Moore, 1959

Superfamily: LICHOIDEA sensu Fortey (Fortey in Kaesler 1997)

Family: LICHIDAE  Hawle & Corda, 1847

Subfamily: TROCHURINAE  Phleger, 1936

Genus BASSEIARGES  Corbacho & López-Soriano, 2013

 

Diagnosis

Adjusted from Corbacho & López-Soriano, 2013

Cephalon
Basseiarges has a rounded cephalon that is subtriangular in form. It is wider than it is long. The genal spines edge runs further over the glabella and splits it in two. The genal spines are longer than the thorax and are oriënted a bit outwards. They have blunt serrations both on top and below. The cheeks are upright and have small tubercules and pits. The eyes are small and are placed low on the fixed cheeks (fixigena).

Thorax
The thorax has 10 or 11 segments. Close to the head, it is wider than close to the tail. The axis is slightly vaulted and well defined. The thoracic pleurae end in strong, straight and sharp tips.

Pygidium
Basseiarges has a pygidium that is large compared to the cephalon (macropygous). It is semicircular in form. It has an axis with only a well-defined axial pygidial ring followed by four additional rings. The edge of the pygidium is high and carries 3 pairs of strong marginal spines. These are rounded in form and quite straight and pointy. The two middle marginal spines are in the postaxis area and these are shorter than the two other pairs. There are 3 pairs of pleural ribs that split the pygidium in parts that end in 2 or 3 tubercles.

 

Occurence

Basseiarges occurs in the Eifelian of Southern Morocco.

 

Recognizing Basseiarges species

There is only one species of Basseiarges described, Basseiarges mellishae (Corbacho & López-Soriano, 2013)


Basseiarges mellishae

Corbacho & López-Soriano, 2013 (Eifelian)

 

Pictures used with permission from Corbacho & López-Soriano

 

The above pictures show two Basseiarges mellishae.

The picture in the middle is a sideview that clearly shows the blunt serrations on top and below the genal spines.

The picture below is showing the backside of the pygidium with pygidial spines and pygidial edge.


References

J. Corbacho and F. J. López-Soriano. 2013. Two new species of Trochurinae trilobites from the Middle Devonian (Eifelian) of Southern Morocco. Batalleria 18:15-24