Home of the Fossil Coralline Algae
ALGAE OF THE KRAPPFELD - GOSAU
(published: Rasser, M., 1994. Facies and palaeoecology of rhodoliths and acervulinid macroids in the Eocene of the Krappfeld (Austria). - Beitrńge zur Palńontologie, 19:191-217.)

Created by Michael Rasser

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Study area:

The Krappfeld (Carinthia, Southern Austria) is situated on the eastern margin of the Gurktal Nappe, belonging to the Upper Austroalpine Unit. The Eocene sediments represent the final deposits of an intraalpine Gosau basin. Calcareous red algae occur in the Lower and Middle Eocene and are associated with Nummulitid and Alveolinid Larger Foraminifera, as well as with acervulinid foraminiferal macroids.


Algae:

Index:

Lithoporella
Lithothamnion
Sporolithon
Pseudolithothamnion

 

Class Rhodophyceae RABENHORST, 1863
Order Corallinales SILVA & JOHANSEN, 1986
Family Corallinaceae LAMOUROUX, 1812
Genus Lithoporella (FOSLIE) FOSLIE, 1909

Dimerous thallus, lacking protuberances.

 

 Lithoporella melobesioides (FOSLIE) FOSLIE, 1909

1904 Mastophora (Lithoporella) melobesioides FOSLIE - WEBER VAN BOSSE & FOSLIE, pp. 73-77, Text-figs. 30-32.
1983c Lithoporella melobesioides (FOSLIE) FOSLIE - BOSENCE, pp. 165-166, Pl. 18, Fig. 1.

Thallus morphology: crustose thallus, partially growing unattached.

Anatomy: can easily be recognized by its unistratose cell layers (predominantly not more than two consecutive layers) composed of large cells. Cell length = 9-16 Ám (mean (M) = 14, standard deviation (SD) = 2.5); cell diameter = 6-16 Ám (M = 10, SD = 2.2); ratio length/diameter = 0.9-2.5 (M = 1.4, SD = 0.4, number of measured cells (N) = 20).

Sporangia: rare; height = 78-126 Ám (M = 104, SD = 20.3); diameter = 40-60 Ám (M = 50, SD = 8.3); ratio height/diameter = 1.9-2.4 (M = 2.1, SD = 0.3, N = 4).

Occurrence: in rhodoliths and macroids of the whole section, but never frequent.

 

Genus Lithothamnion HEYDRICH, 1897

Former name: Lithothamnium PHILIPPI, 1837. Thallus monomerous and plumose. 

Lithothamnion sp.

Thallus morphology: growth form predominantly protuberant, partially growing unattached.

Anatomy: thallus predominantly composed of thin crusts (200-300 Ám). Core filaments well developed and regular. Some derivates of the branched core filaments curve outward, some curve toward the substrate. The core is 88-100 Ám thick. Cell length = 12-22 Ám (M = 16, SD = 2.9); cell diameter = 7-10 Ám (M = 8, SD = 1); ratio cell length/diameter = 1.2-3.1 (M = 1.9, SD = 0.5, N = 15). Cell length of peripheral filaments = 8-13 Ám (M = 12, SD = 1.8); cell diameter = 7-12 Ám (M = 10, SD = 1.5); ratio cell length/diameter = 0.7-1.9 (M = 1.3, SD = 0.3, N = 20).

Sporangia: multiporate conceptacles, restricted to (mostly small) protuberances; height = 174-195 Ám (M = 182, SD = 10.1); diameter = 295-420 Ám (M = 341, SD = 51.5); ratio height/diameter = 0.5-0.6 (M = 0.5, SD = 0.1, N = 5).

Occurrence: only a few occurrences in rhodoliths of the basal horizon of the Lower Rhodolith Accumulation and in the Upper Rhodolith Accumulation.

 

Genus Sporolithon HEYDRICH, 1897

Former name: Archaeolithothamnium ROTHPLETZ, 1891. Thallus monomerous and plumose. Sporangia are small and usually aligned in tiers; persistent groups of calcified filaments are interspersed between the sporangia.

Sporolithon sp. A

Thallus morphology: protuberant, less frequently crustose. Only the protuberances (mean diameter 1.2 mm, mean height 2 mm) contain sporangia. Forming monospecific rhodoliths.

Anatomy: some derivates of the branched core filaments curve outward, but they never curve toward the substrate. Core thickness mostly 100 Ám. Cells rather small and rarely well developed. Cell length of core filaments = 10-32 Ám (M = 19, SD = 6.1); cell diameter = 9-14 Ám (M = 11, SD = 1.4); ratio cell length/diameter = 0.9-3.6 (M = 1.8, SD = 0.7, N = 20). Cell length of peripheral filaments = 13-22 Ám (M = 17, SD = 2.1); cell diameter = 10-15 Ám (M = 12, SD = 1.6); ratio cell length/diameter = 0.9-1.7 (M = 1.4, SD = 0.2, N = 20).

Sporangia: very regular rows with up to 25 ovate conceptacles. Up to six filaments can be interspersed between the sporangia, but they also may join together. The filament walls either curve outward to make place for a sporangium so that it is constructed within one filament, or several filaments end below the sporangia. Height of sporangia = 68-84 Ám (M = 75, SD = 5.4); diameter = 36-49 Ám (M = 42, SD = 4.1); ratio height/diameter = 1.5-2.1 (M = 1.8, SD = 0.2, N = 20).

Occurrence: dominant rhodolith builder. Only the Acervulinid Macroid Accumulation lacks this species.

Remarks: measurements suggest referring this species to Sporolithon lugeoni (PFENDER, 1926). However, a designation of species in the current paper seems inappropriate without a general taxonomic revision of Paleogene coralline algae.

 

Sporolithon sp. B

Thallus morphology: see Sporolithon sp. A; protuberances (diameter: 1-1.5 mm, height: 1 mm ) are smaller than those of S. sp. A.

Anatomy: some derivates of the branched core filaments curve outward, but they never curve toward the substrate. Cells are rather small and rarely well developed. Cell length of the core filaments = 14-30 Ám (M = 20, SD = 4); cell diameter = 7-13 Ám (M = 10, SD = 1.5); ratio cell length/diameter = 1.3-4.3 (M = 2.1, SD = 0.7, N = 20). Cell length of peripheral filaments = 10-14 Ám (M = 11, SD = 1.5); cell diameter = 10-13 Ám (M = 11, SD = 0.9); ratio cell length/diameter = 0.8-1.3 (M = 1, SD = 0.2, N = 20).

Sporangia: usually not more than 15 conceptacles in one row. The rows are generally less regular and the sporangia are more spherical than those of S. sp. A. At the base of the sporangial rows, there is a distinct light row of cells. Up to four filaments are interspersed between the conceptacles, which are not joined to one another. Height of sporangia: 79-108 Ám (M = 93, SD = 8); diameter of sporangia = 41-64 Ám (M = 52, SD = 6); ratio height/diameter = 1.3-2.4 (M = 1.8, SD = 0.3, N = 20)

Occurrence: besides several fragments, only one specimen could be distinguished in a rhodolith from the upper horizon of the Lower Rhodolith Accumulation.

Remarks: measurements suggest referring this species to S. nummuliticum (G▄MBEL) ROTHPLETZ, 1891; for the reasons mentioned above it is not designated.

 

Order Cryptonemiales SCHMITZ in ENGLER, 1892

 Family Peyssonneliaceae DENIZOT, 1968

A recent revision for the Paleogene was undertaken by MOUSSAVIAN (1988).

Genus Pseudolithothamnium PFENDER, 1936

Cell filaments build a median layer parallel to the substrate. Filaments curve outward and toward the substrate (hypothallus). The perithallus is a thin cell layer above the hypothallus. No calcified sporangia are developed.

Pseudolithothamnium album PFENDER, 1936

1936 Pseudolithothamnium album nov. sp. - PFENDER, p. 330, Pl. 19.
1988 Pseudolithothamnium album PFENDER - MOUSSAVIAN, S. 100, Abb. 1, Taf. 2, Abb. 2-3.

Thallus morphology: smooth crusts without protuberances.

Anatomy: superimposed layers with a thickness of more than 0.5 mm each and a golden colour makes this species easy to recognize in thin section. Hypothallus thickness: 100-150 Ám; cells elongated, diameter: 19-26 Ám, length: 22-45 Ám in the centre; about 9-13 Ám in diameter, length: 13-22 Ám in the peripheral region.

Perithallus: 150-200 Ám thick; because of the poor preservation, cells could not be measured. Their dimensions approximately correspond with those of the smaller hypothallus cells.

Occurrence: only in the Lower Rhodolith Accumulation, intergrowing with Sporolithon sp. A. It was found to form only one nearly monospecific peyssonneliacean macroid. Fragments are rare.

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