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Hsuum acutum

Protozoa - Nassellaria - Hsuidae

Discussion

Original description: Test relatively small, conical, with well-developed horn. Cephalis small, conical, covered with layer of microgranular silica. Thorax and abdomen with short, massive, and irregular costae between one or two rows of pore frames. Post-abdominal chambers comprised of long continuous costae, with one or two rows of pore frames between two adjacent costae. Post-abdominal chambers increasing in width more rapidly than increasing in length as added.

Original remarks: Hsuum acutum n. sp. can be distinguished from other Hsuum spp in this report by having a test with apical end very pointed in nature, and by having short, massive, and irregular costae on its earlier chambers.

Etymology: Acutus-a-um (Latin, adj.) pointed.

Taxonomy
Hsuum acutum was named by Yeh (1987). Its type specimen is NMNS (000083) and is a 3D body fossil. Its type locality is Suplee-Izee area, OR-600A, which is in a Toarcian marine tuff/limestone in the Hyde Formation of Oregon.

Synonymy list
YearName and author
1987Hsuum acutum Yeh p. 63 figs. Pl. 16, figs. 5, 12, 17

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RankNameAuthor
Life
Eukaryota()
classProtozoaGoldfuss 1820
subphylumSarcodinaSchmarda 1871
classReticulareaLankester 1885
subclassRadiolaria(Müller 1858)
RankNameAuthor
superorderPolycystina(Ehrenberg 1838)
orderNassellariaEhrenberg 1875
superfamilyArchaeodictyomitraceaPessagno 1976
familyHsuidae
genusHsuumPessagno 1977
speciesacutum

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Hsuum acutum Yeh 1987
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Diagnosis
No diagnoses are available
Measurements
No measurements are available
Composition: silicap
Environment: marinep
Locomotion: passively mobilep
Life habit: planktonicp
Diet: omnivorep
Created: 2005-01-28 01:13:47
Modified: 2005-01-28 03:13:47
Source: p = phylum
Reference: Kiessling 1999

Age range: Early/Lower Toarcian or 184.20000 to 182.90000 Ma

Collections (3 total)


Time interval Ma Country or state Original ID and collection number
Early/Lower Toarcian184.2 - 182.9USA (Oregon) Hsuum acutum (type locality: 124328 124331)
Early/Lower Toarcian184.2 - 182.9Japan Hsuum acutum (124830)