Palaeoaplysina

Palaeoaplysina Temporal range: Upper Carboniferous –Lower Permian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Clade:	Archaeplastida
Division:	Rhodophyta
Class:	Florideophyceae
Stem group:	Corallinales
Order:	† Archaeolithophyllales (?)
Family:	† Palaeoaplysinaceae
Genus:	† Palaeoaplysina

Palaeoaplysina is a genus of tabular, calcified fossils that are a component of many Late Palaeozoic reefs. ^[1] The fossil acted as a baffle to trap sediment. Historically interpreted as a sponge or hydrozoan, ^[2] recent studies are converging to its classification in the coralline stem group, placing it among the red algae. ^[1]

Morphology

The thalloid organism had a series of internal canals opening on one side of the body (presumably the upper side), and volcano-like protuberances on that same side inviting comparison to filter-feeding organisms. On the other hand, it seems to have had a calcified cellular make up akin to that of the coralline reds, suggesting that it was either a stem-group coralline or a coralline-encrusted filter feeder. ^[3]

Distribution

The organism is widespread in the tropical and near-tropical margin of the Laurentian continent (45–15°N), but is not found elsewhere. ^[4] Its oldest reported occurrence is Middle Pennsylvanian (mid- to late Moscovian) ^[5] and youngest is the late Sakmarian. ^[3] It acts as an important reservoir rock for oil deposits. ^[3]

See also

• Coralline algae#Evolution
• Other stem-group corallines:
  • Arenigiphyllum (Ordovician)
  • Petrophyton (Ordovician : Caradoc)
  • Graticula (Silurian : Wenlock)
  • Halysis (Ordovician)
  • Archaeolithophyllum (Pennsylvanian)
  •  ? Maimonachaetetes (Mississippian)
  •  ? Palaeoaplysina (Pennsylvanian – Permian; possibly an animal)
  •  ? Solenoporaceae (Ordovician)

References

1. K. D. Anderson; B. Beauchamp (2011). Development of a Palaeoaplysina Reef Complex, Ellesmere Island, Canadian Arctic (PDF). Recovery – 2011 CSPG CSEG CWLS Convention 1. Archived from the original (PDF) on 2011-09-29. Retrieved 2011-06-14.
2. Davies, G. R.; Nassichuk, W. W. (1973). "The Hydrozoan? Palaeoaplysina from the Upper Paleozoic of Ellesmere Island, Arctic Canada". Journal of Paleontology. 47 (2): 251–265. JSTOR   1302890.
3. Kaylee Anderson, Benoit Beauchamp (2010). The Origin and Ecology of Late Paleozoic Palaeoaplysina in Arctic Canada: An Aberrant Ancestral Coralline Algae (?) that Grew at a Time of High Atmospheric CO₂. GeoCanada. Archived from the original on 2011-03-12. Retrieved 2011-06-14.
4. Vachard, D.; Kabanov, P. (2007). "Palaeoaplysinella gen. Nov. And Likinia Ivanova and Ilkhovskii, 1973 emend., from the type Moscovian (Russia) and the algal affinities of the ancestral palaeoaplysinaceae n. Comb". Geobios. 40 (6): 849–860. doi:10.1016/j.geobios.2007.01.006.
5. Ritter, Scott M.; Morris, Thomas H. (August 1997). "Oldest and Lowest Latitudinal Occurrence of Palaeoaplysina: Middle Pennsylvanian Ely Limestone, Burbank Hills, Utah" . PALAIOS. 12 (4): 397. Bibcode:1997Palai..12..397R. doi:10.2307/3515339. JSTOR   3515339 . Retrieved 11 November 2014.