Analox

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Analox
Temporal range: Botomian (Olenellus-zone)
Analox lindrawing.jpg
Analox bipunctata
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Analox

Rasetti, 1966
species
  • A. bipunctataRasetti, 1966 (type) [1]

Analox Rasetti, 1966 [2] is a genus of Eodiscinid trilobites belonging to the family Weymouthiidae Kobayashi T. (1943), [3] Order Agnostida (Salter 1864) [4] It lived during the Botomian stage. [1] It can easily be distinguished from other trilobites by the two furrows that extend forwards and sidewards from the front of the glabella.

Contents

Distribution

Analox bipunctata is known from the Lower Cambrian of the United States. 42°24′N73°30′W / 42.400°N 73.500°W / 42.400; -73.500 ). [5] [6]

Type locality for Analox bipunctata is Rasetti's (1966) locality cs-4 in an unnamed limestone Formation which is exposed in several outcrops on a hill (Griswold Farm) about 1 mile southeast of North Chatham, Columbia County, New York State, USA; the faunule is referred to as the Acimetopus bilobatus faunule from one of the most common and characteristic trilobites.

Ecology

A. bilobatus occurs in association with other Weymouthiidae ( Acidiscus , Acimetopus , Bathydiscus , Bolboparia , Leptochilodiscus , Serrodiscus ), Calodiscus, several species of Olenellus and Bonnia (Dorypygidae). [5]

Description

Like all Agnostida, Analox is diminutive and the headshield (or cephalon) and tailshield (or pygidium) are of approximately the same size (or isopygous) and outline. Like all Weymouthiidae, it lacks eyes and rupture lines (or sutures). The central raised area of the cephalon (or glabella) tapers forward and has a hardly discernible transverse furrow. Where the lateral portion of the furrow surrounding the glabella bends into the frontal portion, it meets left and right with the merged median and border furrows that extend more outwards than forwards, until these end in a pit some distance from the side. This is a very distinct character of Analox. The large lobe behind this furrow (or L1), extends into a massive, broad based spine that points backward and upwards. The most backwards portion of the glabella, called occipital ring, is indistinct beneath the glabellar spine. The anterior border swollen medially, defined by the furrows running anterolaterally from axial furrow at front of glabella. There is no lateral cephalic border. The posterior border furrow fades out a little in front of genal angle. The pygidium has a long axis (of about eight rings). The pygidial border is narrow and defined by equally narrow border furrow.

Related Research Articles

<i>Acidiscus</i>

Acidiscus Rasetti, 1966, is a genus of Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida Salter (1864). It lived during the Botomian stage = late Lower Cambrian Stage 4 ; the upper Botomian boundary corresponds to base of the Middle Cambrian, Miaolingian Series and Wuliuan stage.

<i>Acimetopus</i>

Acimetopus is a genus of trilobites that lived during the Botomian stage.

<i>Bolboparia</i>

Bolboparia is an extinct genus of eodiscinid agnostid trilobites. It lived during the late Lower Cambrian in what today Canada and the United States.

<i>Ninadiscus</i>

Ninadiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Botomian.

<i>Oodiscus</i>

Oodiscus is an extinct genus of small size trilobite, with three known species. It lived during the Toyonian in what are now Canada and the USA.

Meniscuchus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Botomian stage, which lasted from approximately 522 to 516 million years ago. This faunal stage was part of the Cambrian Period. Meniscuchus has been found in the USA, Canada, Russia and Australia.

Parapagetia is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Botomian stage, which lasted from approximately 524 to 518.5 million years ago. This faunal stage was part of the Cambrian Period.

<i>Dicerodiscus</i>

Dicerodiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the early part of the Botomian stage, in China. Four species have been assigned to it. Dicerodiscus is unique for an eodiscoid in having conspicuous and curved spines that are attached anteriorly, and at their base are directed outward perpendicular to the midline, before gradually bending further backwards.

Semadiscus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It has been collected from the Lower Cambrian of Canada (Newfoundland), Russia, and the United States. Only the headshield is known, and it may well be that it would be better to include it in Serrodiscus.

Egyngolia is a genus of very small sized Trilobites, that lived during the Lower Cambrian in what are today the Russia Federation, Mongolia, and South Australia.

Acmarhachis is a genus of trilobite in the order Agnostida, which lived in what are now Australia, Canada, China (Anhui), Kazakhstan, Russia (Kharaulakh), and the US. It was described by Resser in 1938, and the type species is Acmarhachis typicalis.

<i>Litometopus</i> Extinct genus of trilobites

Litometopus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the Botomian stage.

Marocconus

Marocconus is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It is still debated if it lived at the very end of the Lower Cambrian or at the very beginning of the Middle Cambrian. Marocconus notabilis is the only known species in this genus.

<i>Mallagnostus</i>

Mallagnostus Howell, 1935, is a trilobite genus belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida Salter (1864) according to H. B. Whittington et al. 1997. It lived during the late Lower Cambrian, with remains found in USA, Canada (Newfoundland), Spain, England, Russia, Mongolia, and the early Middle Cambrian as reported from China and Russia (Yakutia).

Weymouthiidae

The Weymouthiidae Kobayashi 1943 are an extinct family of eodiscinid agnostid trilobites. They lived during the late Lower Cambrian and earliest Middle Cambrian in the so-called Olenellus- and Eokochaspis-zones in the former paleocontinents of Laurentia, Avalonia, Gondwana. The Weymouthiidae are all blind and lack free cheeks.

Eodiscidae

Eodiscidae is a family of agnostid trilobites that lived during the final Lower Cambrian and the Middle Cambrian. They are small or very small, and have a thorax of two or three segments. Eodiscidae includes nine genera.

The Hebediscidae are a family of trilobites belonging to the order Agnostida that lived during the Lower Cambrian. They are small or very small, and have a thorax of two or three segments. The Hebediscidae include five genera.

<i>Jinghediscus</i>

Jinghediscus Xiang & Zhang, 1985 is a genus of Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida It lived during the lower Middle Cambrian, with remains found in China (Xinjiang) and Australia (Queensland).

<i>Cedaria</i>

Cedaria is a small, rather flat trilobite with an oval outline, a headshield and tailshield of approximately the same size, 7 articulating segments in the middle part of the body and spines at the back edges of the headshield that reach halflength of the body. Cedaria lived during the early part of the Upper Cambrian (Dresbachian), and is especially abundant in the Weeks Formation.

<i>Serrodiscus</i>

Serrodiscus Richter and Richter 1941. is a genus of Eodiscinid trilobites belonging to the family Weymouthiidae Kobayashi T. (1943), Order Agnostida. It lived during the late Lower Cambrian, with remains found in Canada, China (Gansu), The United Kingdom (England), Germany (Silesia), Poland, the Russian Federation, and the United States. It is named for the spines on the ventral side of the pygidium, which give it a serrated impression.

References

  1. 1 2 Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Trilobita entry)". Bulletins of American Paleontology. 364: 560. Archived from the original on 5 September 2006. Retrieved 12 January 2008.
  2. RASETTI, F., 1966. New Lower Cambrian trilobite faunule from the Taconic sequence of New York. Smithsonian Miscellaneous Collections, 148 (No. 9), 1 - 52, 9 pls.
  3. KOBAYASHI T. 1943. Brief notes on the Eodiscids 1, their classification with a description of a new species and a new variety, Proceedings of the Imperial Academy, Tokyo, Volume 19, pp. 37-42.
  4. SALTER, J. W. 1864: On some new fossils from the Lingula-flags of Wales. Quarterly Journal of the Geological Society of London, 20, 233–241.
  5. 1 2 Paleobiology Database. "East Chatham Quad, unnamed fm., NY (Cambrian of the United States) (trilobite)" . Retrieved 19 December 2012.
  6. Whittington, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida. 1997