Harpetida
Harpetida Temporal range: Furongian–Frasnian PreꞒ Ꞓ O S D C P T J K Pg N | |
---|---|
![]() | |
A Harpetida trilobite from Morocco. | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | †Trilobita |
Subclass: | †Librostoma |
Order: | †Harpetida Whittington, 1959 |
Families | |
|
Harpetida is one of the eleven orders of the extinct arthropod class Trilobita. The first harpetid trilobites appear in the Upper Cambrian, and the last species die out at the end of the Devonian period.
Harpetid trilobites are characterized among trilobites by bearing a comparatively large, semicircular brim around the cephalon (head) which is often perforated by small pores. This brim is thought to serve as a filter-feeding apparatus. The brim stretches backward on either side of the cephalon (head) and typically has a pronounced suture along the outside.
The compound eyes are typically reduced to small tubercles, though they have strong ridges stretching to the glabella (central region of the cephalon). They also typically have 12 or more thoracic segments. The pygidia are usually small.
The families of Harpetida were formerly included in the order Ptychopariida, but were recently given their own order (Ebach & McNamara 2002). The subclass Librostoma was erected in 1990 by Richard Fortey to cover the various orders originally placed within Ptychopariida. The name "Harpidae" was once used as the name for the trilobite family containing the type genus Harpes. However, this is in conflict with the use of the same name for the family of harp snails and that taxon had precedence.
Families and genera
- Entomaspididae
- Baikadamaspis
- Entomaspis (=Hypothetica)
- Harpetidae
- Arraphus
- Bohemoharpes (=Declivoharpes; =Unguloharpes)
- Bowmania
- Brachyhipposiderus
- Conococheaguea
- Dolichoharpes
- Dubhglasina (=Australoharpes; Sinoharpes)
- Eoharpes (/Harpina)
- Eotrinucleus
- Eskoharpes (=Globoharpes?)[1][2]
- Globoharpes(?) [1][2]
- Harpes (=Helioharpes; Reticuloharpes)
- Heterocaryon
- Hibbertia (/Platyharpes; Harpesoides; Metaharpes; Paraharpes; Thorslundops; Wegelinia)
- Kathrynia
- Kielania (=Lowtheria)
- Lioharpes (=Fritchapsis)
- Paleoharpes
- Scotoharpes (=Aristoharpes; Selenoharpes).
- Harpididae
- Chencunia
- Dictyocephalites
- Fissocephalus
- Harpides
- Harpidoides
- Kitatella
- Loganopeltis
- Loganopeltoides
- Metaharpides
- Paraharpides
- Pscemiaspis
References
- ^ a b McNamara, Kenneth J.; Feist, Raimund; Ebach, Malte C. "PATTERNS OF EVOLUTION AND EXTINCTION IN THE LAST HARPETID TRILOBITES DURING THE LATE DEVONIAN (FRASNIAN)". Palaeontology. doi:10.1111/j.1475-4983.2008.00832.x.
- ^ a b Johnson, Robert. G. "Devonian Harpetidae from the central and eastern Anti–Atlas, Morocco". Zootaxa.
External links
- Order Harpetida - from A Guide to the Orders of Trilobites by Sam Gon III
- v
- t
- e
Orders | |
---|---|
Genera |
![Psychopyge elegans](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Psychopyge_elegans.png/100px-Psychopyge_elegans.png)
- Cambrian
- Ordovician
- Silurian
- Devonian
- Carboniferous
- Permian
Earliest |
|
---|---|
Latest |
|
First described | |
Largest |
|
Smallest | Acanthopluerella |
- Alexander von Humboldt
- Joachim Barrande
- Alfred Russel Wallace
- Charles Doolittle Walcott
- Charles Emerson Beecher
- Roderick Murchison
- Adam Sedgwick
- Rudolf Kaufmann
- Rudolf Richter & Emma Richter
- Martin Basse
- Niles Eldredge
- George Frederic Matthew
- Harry B. Whittington
- Brian D. E. Chatterton
- Richard Fortey
- Euan Clarkson
- Franco Rasetti
- Gregory D. Edgecombe
- Bruce S. Lieberman
- Gerald J. Kloc
- Gerhard K. B. Alberti
- Teiichi Kobayashi
- Johan Wilhelm Dalman
- Anti-Atlas Mountains
- Beecher's Trilobite Bed
- Burgess Shale
- Emu Bay Shale
- Gees, Gerolstein
- Hunsrück Slate
- Jince Formation
- Latham Shale
- Llandeilo Group
- Maotianshan Shales
- Silica Shale Formation
- Takaka Terrane
- Walcott–Rust quarry
- Wenlock Group
- Wheeler Shale
- Wolchov River
- Wren's Nest
Exoskeleton |
| ||||
---|---|---|---|---|---|
Soft body parts |
![]() | This Harpetida-related article is a stub. You can help Wikipedia by expanding it. |
- v
- t
- e