Palmer and Repina[1] assigned Gabriellus and Callavia to the Olenelloidea, but the ocular lobes in these two genera circumscribe the entire lateral border of the frontal lobe of the glabella, and thus, do not belong to this superfamily, but to the Judomioidea. Geyer[2] assigned Cambropallas to the Olenelloidea, but it lacks the diagnostic features and appears to be closely related to Andalusiana, and is now considered to be an advanced member of the Nevadioidea.[3]
DistributionEdit
In western Laurentia Fallotaspididae and Archaeaspididae proceed the first Olenelloidea. The Holmiidae occur at the late Atdabanian, and are contemporary with the Nevadioidea. They are followed by Biceratopsidae and Olenellidae.[4]
DescriptionEdit
As with most early trilobites, the Olenelloidea have an almost flat exoskeleton, that is only thinly calcified, and has crescent-shaped eye ridges. As part of the Olenellina suborder, the Olenelloidea lack dorsal sutures. The superfamily can be distinguished from all other Olenellina by features of the cephalon and in particular the glabella. The backward portion of the third lateral lobe of the glabella counted from the back (L3) bulges laterally relative to the first lateral lobe (L1). The front end of the eye lobe (or ocular lobe) is connected only to the back half of the frontal lobe (AL or L4) of the glabella, and merges smoothly with it (rather than merely contacting it). The ocular lobe consists of an inner and outer band.[3]
ReferencesEdit
^Palmer, A. R.; Repina, L. N. (1993). "Through a glass darkly: taxonomy, phylogeny and biostratigraphy of the Olenellina". The University of Kansas Paleontological Contributions. 3: 1–35.
^Geyer, G. (1993). "The giant Cambrian trilobites of Morocco". Beringeria. 8: 71–107.
^ abLieberman, B. S. (1998). "Cladistic analysis of the Early Cambrian olenelloid trilobites". Journal of Paleontology. 72: 59–78. doi:10.1017/S0022336000024021.
^Hollingsworth, J.S. (2006). "Holmiidae (Trilobita: Olenellina) of the Montezuman Stage (Early Cambrian) in Western Nevada". Journal of Paleontology. 80 (2): 309–332. doi:10.1666/0022-3360(2006)080[0309:htootm]2.0.co;2. JSTOR 4095128.
olenelloidea, superfamily, trilobites, group, extinct, marine, arthropods, they, lived, during, late, lower, cambrian, species, occurred, paleocontinents, temporal, range, botomian, toyonian, olenellus, zone, preꞒ, nolenellus, gilbertiscientific, classificatio. The Olenelloidea are a superfamily of trilobites a group of extinct marine arthropods They lived during the late Lower Cambrian and species occurred on all paleocontinents OlenelloideaTemporal range Botomian Toyonian Olenellus zone PreꞒ Ꞓ O S D C P T J K Pg NOlenellus gilbertiScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ArthropodaClass TrilobitaOrder RedlichiidaSuborder OlenellinaSuperfamily OlenelloideaWalcott 1890FamiliesOlenellidae Biceratopsidae Holmiidaestem group genera Elliptocephala Wanneria Fritzolenellus Mummaspis Laudonia Contents 1 Taxonomy 2 Distribution 3 Description 4 ReferencesTaxonomy EditPalmer and Repina 1 assigned Gabriellus and Callavia to the Olenelloidea but the ocular lobes in these two genera circumscribe the entire lateral border of the frontal lobe of the glabella and thus do not belong to this superfamily but to the Judomioidea Geyer 2 assigned Cambropallas to the Olenelloidea but it lacks the diagnostic features and appears to be closely related to Andalusiana and is now considered to be an advanced member of the Nevadioidea 3 Distribution EditIn western Laurentia Fallotaspididae and Archaeaspididae proceed the first Olenelloidea The Holmiidae occur at the late Atdabanian and are contemporary with the Nevadioidea They are followed by Biceratopsidae and Olenellidae 4 Description EditAs with most early trilobites the Olenelloidea have an almost flat exoskeleton that is only thinly calcified and has crescent shaped eye ridges As part of the Olenellina suborder the Olenelloidea lack dorsal sutures The superfamily can be distinguished from all other Olenellina by features of the cephalon and in particular the glabella The backward portion of the third lateral lobe of the glabella counted from the back L3 bulges laterally relative to the first lateral lobe L1 The front end of the eye lobe or ocular lobe is connected only to the back half of the frontal lobe AL or L4 of the glabella and merges smoothly with it rather than merely contacting it The ocular lobe consists of an inner and outer band 3 References Edit Palmer A R Repina L N 1993 Through a glass darkly taxonomy phylogeny and biostratigraphy of the Olenellina The University of Kansas Paleontological Contributions 3 1 35 Geyer G 1993 The giant Cambrian trilobites of Morocco Beringeria 8 71 107 a b Lieberman B S 1998 Cladistic analysis of the Early Cambrian olenelloid trilobites Journal of Paleontology 72 59 78 doi 10 1017 S0022336000024021 Hollingsworth J S 2006 Holmiidae Trilobita Olenellina of the Montezuman Stage Early Cambrian in Western Nevada Journal of Paleontology 80 2 309 332 doi 10 1666 0022 3360 2006 080 0309 htootm 2 0 co 2 JSTOR 4095128 nbsp Paleontology portal nbsp This Redlichiida related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Olenelloidea amp oldid 1040478676, wikipedia, wiki, book, books, library,
