Nannotax3 - ntax_Farinacci - Hyalolithus tumescens Nannotax3 - ntax_Farinacci - Hyalolithus tumescens

CATALOG - Hyalolithus tumescens


Folder trail: ntax_Farinacci -> Haptophytes -> Hyalolithus -> Hyalolithus tumescens
Folders this level: H. neolepis, H. tumescens

Original descriptions of taxa. For coccolithophores, and many calcispheres, these are pages from the Farinacci & Howe Catalog of Calcareous Nannofossils. In other cases (e.g. non-calcifying haptophytes) the data is directly compiled on this site. The "Catalogue of Calcareous Nannofossils" was originally compiled by Prof A. Farinacci 1969-1989, since 2000 it has been updated and extended by Richard Howe - see The Farinacci and Howe Catalog - an Introduction.
Taxa are sorted alphabetically for simple browsing, or you can use search boxes at the top & bottom of the page




Current identification/main database link: Hyalolithus tumescens Abe et al. 2016

Compiled data

Citation: Hyalolithus tumescens Abe et al. 2016
Taxonomic rank: species
Type specimens: Distal view of scale (Fig. 2: 4).
Type sample (& lithostrat): Distal view of scale (Fig. 2: 4). Slide deposited in the National Science Museum, Tokyo. England Finder Reference: R26/3.
Type age (chronostrat): Middle Eocene
Standardised type level: 102_MIDDLE EOCENE
Type locality: Chalky Mount, Barbados.
Type repository: National Science Museum, Tokyo
Repository Country: Japan
Farinacci catalog page (& compiler): n/a
Current citation: Hyalolithus tumescens Abe et al. 2016


Original Description

Diagnosis. A fossil species of Hyalolithus characterized by scales with an indentation on one side of the central mound in distal view and an off-centre swelling seen in proximal view.

Description. Solid siliceous scales, circular to elliptical in shape. On distal side, scale with prominent marginal rim and perforated central mound, separated by narrow to wide hyaline area. Perforated area consists of about 30–150 circular to elliptical openings (pores) of variable size. One side of central mound with indentation and pit-like depression, always on long axis. On proximal side, perforated central area surrounded by hyaline margin. Swelling (corresponding to pit-like depression on distal side), perforated around the base, situated on long axis.

Size:
Scales 7.0–11.0 μm long, 5.5–9.4 μm wide. Openings 0.2–1.2 μm long. Swelling 0.9–2.1 μm in diameter.

Etymology:
With reference to the swollen structure seen in proximal view; tumescens (L.) = swelling.

Extra details from original publication
Occurrence. Also found in samples from Springfield (Barbados) and Kellogg Shale (California) in this study.

Remarks. The siliceous scales of the type species Hyalolithus neolepis, like those of H. tumescens sp. nov., are solid, circular to elliptical in shape, with a prominent marginal rim and perforated central mound, separated by a narrow to wide hyaline area. However, the scales of H. neolepis are generally much smaller in size (2.9–7.9 μm long, 2.8–7.0 μm wide), with more (about 45–350) but smaller (0.1–0.3 μm long) openings. A small pit-like depression occurs rarely between the two central mounds on the distal side, with a corresponding centrally placed swelling (0.5– 0.7 μm in diameter) on the proximal side. The swelling is perforated seemingly all over the surface, whereas that of H. tumescens is perforated only near the base. We chose the word ‘swelling’ because it is part of the perforated surface not a separate structure and is thus unlike the hollow imperforate tube as seen in the exothecal coccoliths of Syracosphaera pulchra Lohmann.

References:

Abe, K., Tsutui, H. & Jordan, R. W. (2016). Hyalolithus tumescens sp. nov., a siliceous scale-bearing haptophyte from the middle Eocene. Journal of Micropalaeontology. 35: 143-149. gs


nannotaxlogo400px

Hyalolithus tumescens: Catalog entry compiled by Jeremy Young. Viewed: 17-2-2025

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=54774 Go to Archive.is to create a permanent copy of this page - citation notes
nannotaxlogo400px

Nannotax is being sponsored through 2024 by Woodside Energy and Shell USA

Add Comment

* Required information
Captcha Image

Comments

No comments yet. Be the first!