Heterocentrotus

Heterocentrotus
Temporal range: Miocene–recent, 15.97–0 Ma[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Echinoidea
Order: Camarodonta
Family: Echinometridae
Genus: Heterocentrotus
Brandt, 1835
Species

2 species (see text)

Heterocentrotus is a genus of the familia Echinometridae.[2] They are mainly found in the Indo-Pacific basin, especially in Reunion or Hawaii. This genus appeared in the Miocene and spread throughout the warm Indo-Pacific.

Description

test of Heterocentrotus mamillatus

Heterocentrotus are brightly colored tropical sea urchins with very thick spines that have given them the nickname "slate pencil urchins", named after slate pencil..

The genus consists of sea urchins with rounded (but slightly elliptical) test, with the peristome (mouth) located in the center of the oral surface (lower) and the periproct at opposite, at the apex of the aboral (upper) face.

The apical disc is dicyclic, with a reduced periproct. The peristome is also reduced and elliptical, with limited mouth notches. The ambulacrum are polygeminate, with between 9 and 14 pairs of pores per plate, arranged in more or less regular arcs, sometimes almost in bands. All ambulacral plates bear a single, large primary tubercle, occupying almost the entire surface of the plate. The interambulacral plates bear a single, massive nipple, flanked by secondary tubercles on the aboral surface. The radioles are very thick and dense, usually three-faceted (or two or four, or round, mainly in H. mamillatus). They are never modified into scales or plates (unlike Colobocentrotus), but the secondary, short radioles can have an almost rounded shape

List of species

This genus contains two species:[2]

Image Scientific name Distribution
Heterocentrotus mamillatus (Linnaeus, 1758) Indo-Pacific region (from the east coast of Africa to the Pacific archipelagos),
Heterocentrotus trigonarius (Lamarck, 1816) Indo-Pacific region.

These two species are very close visually, and often difficult to distinguish, since they generally share the same distribution area.[3] The main criteria for in situ identification are the radioles, which are generally longer (especially on the aboral side) and more clearly triangular in H. trigonarius, which never has bifacial radioles on its underside. H. trigonarius is also usually darker (brown, dark orange...), but the great variability of colorations in this genus makes this criterion delicate. H. mamillatus often has the secondary radioles white or the base of the primary radioles surrounded by a white ring, which never seems to be seen in H. trigonarius, which is almost always entirely monochromatic (with perhaps the test being slightly darker than the radioles primary). Mamillatus radioles also often bear lighter rings, which does not seem to be seen in H. trigonarius either.

Skeletal-wise, H. mamillatus has less petalloid aboral ambulacral zones than its sister species, and fewer pore pairs per ambulacral plate (9-12 versus 15-16).

References

  1. ^ "Heterocentrotus Brandt 1835". Paleobiology Database. Fossilworks. Retrieved 22 October 2023.
  2. ^ a b Kroh A, Mooi R, eds. (2023). "Heterocentrotus Brandt, 1835". World Echinoidea Database. World Register of Marine Species. Retrieved 22 October 2023.
  3. ^ "Acrocladia". Natural History Museum. Retrieved 2022-11-13.


Read other articles:

Prof. (emeritus) Ir. H. Achmad Baihaki M.Sc. Ph.D.Lahir31 Desember 1935 (umur 88)SerangKebangsaanIndonesiaPendidikanS3AlmamaterUniversity of Minnesota, USA, Dept. of Agronomy and Plant Genetics (1975) Prof. (emeritus) Ir. H. Achmad Baihaki M.Sc. Ph.D., adalah Guru Besar Universitas Padjadjaran sekaligus penggagas ilmu pemuliaan tanaman di Universitas Padjadjaran. Beliau lahir dan besar di Serang, 31 Desember 1935 (usia 84 tahun). Sepanjang karirnya sebagai akademisi dan peneliti, pada m...

 

Kevin CostnerKevin CostnerLahirKevin Michael Costner18 Januari 1955 (umur 69)Lynwood, California, U.S.PekerjaanActorprodusersutradarapemusikTahun aktif1974–sekarangKaryaFilmografiSuami/istriCindy Silva ​ ​(m. 1978; c. 1994)​Christine Baumgartner ​ ​(m. 2004)​Anak7PenghargaanDaftar lengkap Kevin Michael Costner (lahir 18 Januari 1955) adalah seorang aktor, produser, dan sutradara film Amerika. Dia t...

 

فضيحة الصندوق السيادي الماليزي البلد ماليزيا  تعديل مصدري - تعديل   فضيحة الصندوق السيادي الماليزي أو فضيحة صندوق وان إم دي بي السيادي (بالإنجليزية: 1Malaysia Development Berhad scandal)‏ هي فضيحة سياسية قائمة تحدث في ماليزيا. في عام 2015، اتُّهم رئيس الوزراء الماليزي آنذاك نجيب رزاق بت...

2019 Russian crewed spaceflight to the ISS Soyuz MS-13The Soyuz MS-13 approaches the ISSMission typeCrewed mission to ISSOperatorRoskosmosCOSPAR ID2019-041A SATCAT no.44437Mission duration200d 16h 44mOrbits completed3,216 [1] Spacecraft propertiesSpacecraftSoyuz-MSSpacecraft typeSoyuz-MS 11F747 No. 746ManufacturerRKK Energia CrewCrew size3MembersAleksandr SkvortsovLuca ParmitanoLaunchingAndrew R. MorganLandingChristina KochCallsignCliff Start of missionLaunch date20 July 2019, 16:28:2...

 

This biography of a living person needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately from the article and its talk page, especially if potentially libelous.Find sources: David Schechter – news · newspapers · books · scholar · JSTOR (March 2024) (Learn how and when to remove this template message) American journalis...

 

Pour les articles homonymes, voir Saint-Julien et Ance. Saint-Julien-d'Ance Saint-Julien-d'Ance en 2017. Administration Pays France Région Auvergne-Rhône-Alpes Département Haute-Loire Arrondissement Le Puy-en-Velay Intercommunalité Communauté d'agglomération du Puy-en-Velay Maire Mandat Gérard Triolaire 2020-2026 Code postal 43500 Code commune 43201 Démographie Populationmunicipale 247 hab. (2021 ) Densité 14 hab./km2 Géographie Coordonnées 45° 18′ 17″...

This template does not require a rating on Wikipedia's content assessment scale.It is of interest to the following WikiProjects:International relations This template is within the scope of WikiProject International relations, a collaborative effort to improve the coverage of International relations on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.International relationsWikipedia:WikiProject Internatio...

 

Norðurland vestraNorðurland Vestra berwarna merah jambu (nomor 5)NegaraIslandiaIbu kotaSauðárkrókurLuas • Total12,737 km2 (4,918 sq mi)Populasi (2007) • Total7,810 • Kepadatan0,6/km2 (2/sq mi) Norðurland vestra adalah satu dari delapan region tradisional di Islandia, terletak di sisi utara pulau ini. Kota terbesar di region ini ialah Sauðárkrókur dengan populasi 3.000 jiwa. lbsRegion dan County di IslandiaWilayah Statistik&...

 

Athletic teams of California State University, San Bernardino Cal State San Bernardino YotesUniversityCalifornia State University, San BernardinoConferenceCCAANCAADivision IIPresidentTomás D. MoralesAthletic directorShareef AmerLocationSan Bernardino, CaliforniaFirst season1984Varsity teams10 (4 men's, 6 women's)MascotCody CoyoteNicknameYotesColorsBlue, black, and white     Websitecsusbathletics.comTeam NCAA championships1Individual and relay NCAA champions...

銮披汶·頌堪แปลก พิบูลสงคราม第3任泰國總理任期1938年12月16日—1944年8月1日君主國王拉玛八世前任披耶帕凤侯爵继任寬·阿派旺第8任泰國總理任期1948年4月8日—1957年9月16日君主國王拉玛九世前任寬·阿派旺继任乃朴·沙拉信 个人资料出生貝·基達桑卡(1897-07-14)1897年7月14日 暹罗暖武里府逝世1964年6月11日(1964歲—06—11)(66歲) 日本神奈川縣相模原市国籍&#...

 

莎拉·阿什頓-西里洛2023年8月,阿什頓-西里洛穿著軍服出生 (1977-07-09) 1977年7月9日(46歲) 美國佛羅里達州国籍 美國别名莎拉·阿什頓(Sarah Ashton)莎拉·西里洛(Sarah Cirillo)金髮女郎(Blonde)职业記者、活動家、政治活動家和候選人、軍醫活跃时期2020年—雇主內華達州共和黨候選人(2020年)《Political.tips》(2020年—)《LGBTQ國度》(2022年3月—2022年10月)烏克蘭媒�...

 

Unincorporated community in Pennsylvania, United StatesCracker Jack, PennsylvaniaUnincorporated communityCracker Jack, PennsylvaniaCoordinates: 40°10′03″N 79°57′52″W / 40.16750°N 79.96444°W / 40.16750; -79.96444CountryUnited StatesStatePennsylvaniaCountyWashingtonElevation846 ft (258 m)Time zoneUTC-5 (Eastern (EST)) • Summer (DST)UTC-4 (EDT)Area code724GNIS feature ID1172587[1] Cracker Jack is an unincorporated community in Ca...

Computer built using discrete transistors IBM 1620 A transistor computer, now often called a second-generation computer,[1] is a computer which uses discrete transistors instead of vacuum tubes. The first generation of electronic computers used vacuum tubes, which generated large amounts of heat, were bulky and unreliable. A second-generation computer, through the late 1950s and 1960s featured circuit boards filled with individual transistors and magnetic-core memory. These machines r...

 

International athletics championship eventJunior men's race at the 1999 IAAF World Cross Country ChampionshipsOrganisersIAAFEdition27thDateMarch 28Host cityBelfast, Northern Ireland, United Kingdom VenueBarnett Demesne/Queen’s University Playing FieldsEvents1Distances8.012 km – Junior menParticipation154 athletes from 43 nations← 1998 Marrakech 2000 Vilamoura → The Junior men's race at the 1999 IAAF World Cross Country Championships was held at the Barnett Demesne/Queen’s Un...

 

2010 Lambeth Council election ← 2006 6 May 2010 2014 → All council seats   First party Second party   Lib Leader Steve Reed Ashley Lumsden Party Labour Liberal Democrats Leader since September 2002 May 2006 Leader's seat Brixton Hill Streatham Hill Last election 39 seats, 39.7% 17 seats, 29.1% Seats won 44 15 Seat change 5 2 Popular vote 53,925 36,458 Percentage 41.8% 28.3% Swing 2.1% 0.8%   Third party Fourth party   Co...

Social folk dance with mixed European origins Contra dancers at the 2019 Flurry Festival Contra dance (also contradance, contra-dance and other variant spellings) is a form of folk dancing made up of long lines of couples. It has mixed origins from English country dance, Scottish country dance, and French dance styles in the 17th century. Sometimes described as New England folk dance or Appalachian folk dance, contra dances can be found around the world, but are most common in the United Stat...

 

Charles Q. Brown Jr.Jenderal Charles Q. Brown Jr. pada tahun 2020JulukanCQLahir1962 (umur 61–62)San Antonio, Texas, Amerika SerikatPengabdian Amerika SerikatDinas/cabangAngkatan Udara Amerika SerikatLama dinas1984–SekarangPangkatJenderalPerang/pertempuranPerang Melawan Teror Charles Quinton Brown Jr.[1] (kelahiran 1962) adalah seorang jenderal bintang empat Angkatan Udara Amerika Serikat yang sekarang menjabat sebagai kepala staf Angkatan Udara ke-22. Ia adalah ...

 

Cameroonian footballer Gaël Ondoua Ondoua with Anzhi Makhachkala in 2018Personal informationFull name Gaël Nesterovich Bella Ondoua[1]Date of birth (1995-11-04) 4 November 1995 (age 28)Place of birth Yaoundé, Cameroon[2]Height 1.87 m (6 ft 2 in)Position(s) Defensive midfielderTeam informationCurrent team ServetteNumber 5Youth career0000–2014 Lokomotiv MoscowSenior career*Years Team Apps (Gls)2014–2015 CSKA Moscow 0 (0)2016–2017 Vejle BK 23 (2)2017�...

هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (مارس 2021) فالهايم (بالإنجليزية: Valheim)‏  المطور Iron Gate Studio الناشر كوفي ستاين ستوديوز الموزع ستيم،  وآب ستور  محرك اللعبة يونيتي (محرك ألعاب) النظام مايكروسوفت ويند�...

 

American baseball player (born 1941) Baseball player Andy KoscoOutfielderBorn: (1941-10-05) October 5, 1941 (age 82)Youngstown, Ohio, U.S.Batted: RightThrew: RightMLB debutAugust 13, 1965, for the Minnesota TwinsLast MLB appearanceJuly 30, 1974, for the Cincinnati RedsMLB statisticsBatting average.236Home runs73Runs batted in267 Teams Minnesota Twins (1965–1967) New York Yankees (1968) Los Angeles Dodgers (1969–1970) Milwaukee Brewers (1971) California A...