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Morania confluens









3D animation of Morania confluens (being grazed by Wiwaxia corrugata).
ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM
3D model of Morania confluens.
ANIMATION BY PHLESCH BUBBLE © ROYAL ONTARIO MUSEUM
Morania confluens (USNM 35389) – Syntype. Typical specimen showing large perforations. Specimen length (largest specimen) = 80 mm. Specimen dry – direct light. Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTO: JEAN-BERNARD CARON
Morania elongata (USNM 35393) – Syntype. Overview and close up of a large colony. Specimen length (largest specimen) = 173 mm. Specimen dry – polarized light (left), wet – direct light (middle and right). Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON
Morania fragmenta (USNM 35394) – Syntype. General aspect of this species. Width of slab = 84 mm. Specimen dry – polarized light (left), wet – direct light (right). Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON
Morania parasitica (USNM 57718) – Syntype. Encrusted (?) colony on the carapace of the animal Hurdia victoria (the whitish spots). Specimen length (Hurdia) = 104 mm. Specimen wet – direct light. Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTO: JEAN-BERNARD CARON
Morania confluens (USNM 322326-slide 81) – Syntype. Thin section of shale made by C.A. Davies for Walcott�۪s studies showing strings of filaments attributed to this species. Dimension of the slide 24X18 mm (the close up area, the white frame on the slide is 2.4X1.6mm). Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON
Morania costellifera (USNM 35392) – Syntype. Typical specimen showing undulations. Specimen diameter = 15 mm. Specimen dry – direct light. Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTO: JEAN-BERNARD CARON
Morania? reticulata (USNM 35402) – Syntype. Specimen mixed with other organisms showing a mesh-like texture. This species was regarded by Walcott to belong presumably to the genus Morania. Width of slab = 86 mm. Specimen dry – direct light (left), wet – polarized light (right). Walcott Quarry.
© SMITHSONIAN INSTITUTION – NATIONAL MUSEUM OF NATURAL HISTORY. PHOTOS: JEAN-BERNARD CARON
Taxonomy:
Walcott (1919) considered Morania to be related to the modern cyanobacteria Nostoc. No revisions to the affinities of this cyanobacterium have been published since.
Morania – from Moraine Lake (1,885 m), in Banff National Park.
confluens – from the Latin fluere, “flow or stream,” and the prefix con, “together.” The name refers to the abundance of this species.
Burgess Shale and vicinity: M. costellifera Walcott, 1919; M. elongata Walcott, 1919; M. fragmenta Walcott, 1919; M.? globosa Walcott, 1919; M. parasitica Walcott, 1919; M.? reticulata Walcott, 1919, all from the Walcott Quarry.
Other deposits: M.? antiqua Fenton and Fenton, 1937 from the middle Proterozoic Altyn Limestone of Montana and the Little Dal Group, Mackenzie Mountains (see Hofmann and Aitken, 1979).
Age & Localities:
The Walcott Quarry on Fossil Ridge.
History of Research:
Walcott described Morania, erecting eight species, in a 1919 paper along with Burgess Shale algae, comparing the genus to the extant cyanobacteria Nostoc. Walcott included thin sections and details of the microstructures of M. confluens showing that it was formed of tangled strings of pyrite. Satterthwait (1976) studied specimens of M. confluens from the Geological Survey of Canada collections as part of her PhD thesis and broadly agreed with Walcott’s original interpretations, in particular regarding a position within the Nostocaceae. Sattertwhait’s work has not been published but she suggested that many species erected by Walcott might not be valid and could represent parts of more complex algae. Mankiewicz (1992) re-observed Walcott’s thin sections and confirmed the presence of Morania in several samples. Rigby (1986) identified M.? frondosa Walcott 1919, as a sponge and reassigned it to a new genus (see Crumillospongia frondosa).
Description:
Morania ranges in shape from spherical to sheet-like. The sheet-like form M. confluens is by far the most common species. Specimens typically range in length between 1 to more than 13 centimeters. The sheets are characteristically perforated, with holes up to 3 centimeters in diameter. The shape, size, number and distribution of holes are highly variable. Thin sections show that the microstructure of M. confluens is represented by a tangle mass of filaments called trichomes. These filaments have a beadlike structure with little spheroids of pyrite ranging 3 to 7 micrometers in diameter, and originally interpreted by Walcott as defining cellular structures.
Estimating the abundance of Morania is difficult since some bedding planes have large tangled masses of this cyanobacterium, and many could represent fragments of the same colony. Morania is very common in the Walcott Quarry and represents 4.9% of the community (Caron and Jackson, 2008).
Ecology:
Caron and Jackson (2006) suggested that Morania covered large areas of the benthos and might have provided a stable substrate and food source for benthic animals, in particular for a number of grazers, like Odontogriphus and Wiwaxia.
References:
CARON, J.-B. AND D. A. JACKSON. 2006. Taphonomy of the Greater Phyllopod Bed Community, Burgess Shale. Palaios, 21: 451-465.
CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.
HOFMANN, H. J. AND J. D. AITKEN. 1979. Precambrian biota from the Little Dal Group, Mackenzie Mountains, northwestern Canada. Canadian Journal of Earth Sciences, 16: 150-166.
MANKIEWICZ, C. 1992. Obruchevella and other microfossils in the Burgess Shale: preservation and affinity. Journal of Paleontology, 66(5): 717-729.
SATTERTHWAIT, D. F. 1976. Paleobiology and Paleoecology of Middle Cambrian Algae from Western North America. Unpublished PhD thesis, California, Los Angeles, 120 p.
WALCOTT, C. 1919. Cambrian Geology and Paleontology IV. Middle Cambrian Algae. Smithsonian Miscellaneous Collections, 67(5): 217-260.
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