Trilobite - Zilchovaspis rugosa
SKU:
ITEM # TRILO-Morocco-0007
$700.00
$700.00
Devonian - 395-345 mya
Alnif, Morocco
ITEM # TRILO-Morocco-0007
An excellent example of the phacopid trilobite Zilchovaspis rugosa from the Devonian of Morocco. It is a member of the Order Phacopida, Family Dalmanitdae. While most frequently known in the fossil trade as "Odontochile", this one is actually Zilchovaspis.
Phacopida ("Lens-face") is an order of trilobite that lived from the Ordovician to the Devonian. It is made up of a morphologically diverse group of related suborders.
The origin of the Phacopida order is uncertain. It comprises three suborders (Phacopina, Calymenina, and Cheirurina) which share a distinctive protaspis (developmental stage lacking segments) type. The Cheirurina and Calymenina retain a rostral plate (an apomorphy) but in virtually all Phacopina the free cheeks are yoked as a single piece. This sort of similarity in development suggests phylogenetic unity. The suborder Calymenina is the most primitive of the Phacopida order and shares some characteristics with the order Ptychopariida, though it is not included in the subclass Libristoma.
Phacopida had 8 to 19 thoracic segments and are distinguishable by the expanded glabella, short or absent preglabellar area, and schizochroal (Phacopina) or holochroal (Cheirurina and Calymenina) eyes. Schizochroal eyes are compound eyes with up to around 700 separate lenses. Each lens has an individual cornea which extended into a rather large sclera. The development of schizochroal eyes in phacopid trilobites is an example of post-displacement paedomorphosis. The eyes of immature holochroal Cambrian trilobites were basically miniature schizochroal eyes. In Phacopida, these were retained, via delayed growth of these immature structures (post-displacement), into the adult form.
This Zilchovaspis rugosa from near Alnif, Morocco exhibits detailed articulation and inflated three-dimensionality.This preparation of this specimen exhibits the fine facet preservation in the eyes of this specimen.
The most diagnostic features of this taxon are the parabolic cephalon and pygidial spine. Odontochile has a more circular cephalic outline, and a shorter, broadly-based pygidial spine. Both genera bear a strong resemblance to the contemporary genus Huntonia from the Devonian of Oklahoma.
The specimen measures approximately 2 3/4 inches long (over 3 inches if outstretched) on a matrix measuring 2 1/8 by 3 1/2 inches and is prepared in the classic "flying" pose.
Alnif, Morocco
ITEM # TRILO-Morocco-0007
An excellent example of the phacopid trilobite Zilchovaspis rugosa from the Devonian of Morocco. It is a member of the Order Phacopida, Family Dalmanitdae. While most frequently known in the fossil trade as "Odontochile", this one is actually Zilchovaspis.
Phacopida ("Lens-face") is an order of trilobite that lived from the Ordovician to the Devonian. It is made up of a morphologically diverse group of related suborders.
The origin of the Phacopida order is uncertain. It comprises three suborders (Phacopina, Calymenina, and Cheirurina) which share a distinctive protaspis (developmental stage lacking segments) type. The Cheirurina and Calymenina retain a rostral plate (an apomorphy) but in virtually all Phacopina the free cheeks are yoked as a single piece. This sort of similarity in development suggests phylogenetic unity. The suborder Calymenina is the most primitive of the Phacopida order and shares some characteristics with the order Ptychopariida, though it is not included in the subclass Libristoma.
Phacopida had 8 to 19 thoracic segments and are distinguishable by the expanded glabella, short or absent preglabellar area, and schizochroal (Phacopina) or holochroal (Cheirurina and Calymenina) eyes. Schizochroal eyes are compound eyes with up to around 700 separate lenses. Each lens has an individual cornea which extended into a rather large sclera. The development of schizochroal eyes in phacopid trilobites is an example of post-displacement paedomorphosis. The eyes of immature holochroal Cambrian trilobites were basically miniature schizochroal eyes. In Phacopida, these were retained, via delayed growth of these immature structures (post-displacement), into the adult form.
This Zilchovaspis rugosa from near Alnif, Morocco exhibits detailed articulation and inflated three-dimensionality.This preparation of this specimen exhibits the fine facet preservation in the eyes of this specimen.
The most diagnostic features of this taxon are the parabolic cephalon and pygidial spine. Odontochile has a more circular cephalic outline, and a shorter, broadly-based pygidial spine. Both genera bear a strong resemblance to the contemporary genus Huntonia from the Devonian of Oklahoma.
The specimen measures approximately 2 3/4 inches long (over 3 inches if outstretched) on a matrix measuring 2 1/8 by 3 1/2 inches and is prepared in the classic "flying" pose.