Mandagery Sandstone

Mandagery Sandstone
Stratigraphic range: Late Frasnian? - early Famennian?
TypeGeological formation
Unit ofNangar Subgroup, Hervey Group
UnderliesPipe Formation
OverliesKadina Formation
Lithology
PrimarySandstone, Siltstone
Location
LocationCanowindra, New South Wales
RegionNew South Wales
Country Australia
Cast of the slab found in 1956, that preserves 114 fish individuals, which died when their freshwater pond dried up. Most of the individuals in the slab are the placoderms Remigolepis walkeri and Bothriolepis yeungae. One sarcopterygian individual is present, Canowindra grossi, the largest fish in the slab. Two small and inconspicuous juvenile Groenlandaspis are also preserved.[1]

The Mandagery Sandstone is a Late Devonian geological formation in New South Wales, Australia. It is one of several famed Australian lagerstätten, with thousands of exceptional fish fossils found at a site near the town of Canowindra.

A sandstone block containing 114 fish was discovered in 1956 about 10 km west of Canowindra, on the road to Gooloogong. The Canowindra site was rediscovered by paleontologist Alex Ritchie in 1993, and over 3000 fish fossils have been catalogued and stored at the Australian Museum in Sydney[2] and the local Age of Fishes Museum in Canowindra. Antiarch placoderms make up the majority of specimens recovered; Bothriolepis and Remigolepis are the most abundant fossils, followed by the arthrodire Groenlandaspis. About 20 sarcopterygian (lobe-finned fish) fossils have also been found, including new taxa such as Canowindra, Mandageria,[2] Cabonnichthys,[3] Soederberghia[4] and Gooloogongia.[5] Fossils are preserved as natural moulds in the hard sandstone, filled by a mixture of sandstone, clay, and rare fragments of remaining bone. The detail of preservation is high, with individual armor plates, scales, and the internal structures of major bones all visible in latex casts produced from the moulds.[2][6][4]

The Mandagery Sandstone is part of the Hervey Group, a cluster of deformed Paleozoic sediments located near the center of the Lachlan Fold Belt in New South Wales. It is mostly fine-grained red orthoquartzite sandstone, arranged into a number of short sequences. Towards the top of each sequence, the red sandstone is supplanted by thin beds of white sandstone and red siltstone. Cross-bedding and mudcracks indicate that the sandstone was deposited close to the shore.[7]

  1. ^ Gennatas, Lou-Andrea (2022-03-28). Geochronology and provenance of the Late Devonian Canowindra fish bed, Lachlan Orogen (thesis thesis). Macquarie University. doi:10.25949/19432913.v1.
  2. ^ a b c Johanson, Zerina; Ahlberg, Per Erik (1997). "A new tristichopterid (Osteolepiformes: Sarcopterygii) from the Mandagery Sandstone (Late Devonian, Famennian) near Canowindra, NSW, Australia". Transactions of the Royal Society of Edinburgh: Earth Sciences. 88 (1): 39–68. doi:10.1017/S0263593300002303. ISSN 0263-5933. S2CID 130382171.
  3. ^ Ahlberg, Per E.; Johanson, Zerina (1997-12-15). "Second tristichopterid (Sarcopterygii, Osteolepiformes) from the Upper Devonian of Canowindra, New South Wales, Australia, and phylogeny of the Tristichopteridae". Journal of Vertebrate Paleontology. 17 (4): 653–673. Bibcode:1997JVPal..17..653A. doi:10.1080/02724634.1997.10011015. ISSN 0272-4634.
  4. ^ a b Ahlberg, Per E.; Johanson, Zerina; Daeschler, Edward B. (2001-03-26). "The late Devonian lungfish Soederberghia (Sarcopterygii, Dipnoi) from Australia and North America, and its biogeographical implications". Journal of Vertebrate Paleontology. 21 (1): 1–12. doi:10.1671/0272-4634(2001)021[0001:TLDLSS]2.0.CO;2. ISSN 0272-4634. S2CID 130513725.
  5. ^ Johanson, Zerina; Ahlberg, Per E. (1998). "A complete primitive rhizodont from Australia". Nature. 394 (6693): 569–573. Bibcode:1998Natur.394..569J. doi:10.1038/29058. ISSN 1476-4687. S2CID 4401180.
  6. ^ Johanson, Zerina (1997). "New Remigolepis (Placodermi; Antiarchi) from Canowindra, New South Wales, Australia". Geological Magazine. 134 (6): 813–846. Bibcode:1997GeoM..134..813J. doi:10.1017/S0016756897007838. ISSN 0016-7568. S2CID 140654404.
  7. ^ Conolly, J. R. (1965). "Petrology and origin of the Hervey group, upper devonian, Central New South Wales". Journal of the Geological Society of Australia. 12 (1): 123–166. Bibcode:1965AuJES..12..123C. doi:10.1080/00167616508728589. ISSN 0016-7614.