Talk:Permian–Triassic extinction event/notes

Reduviasporonites is alga, not fungus.

However, the study provided insufficient information to ascertain whether the base of Unit IV is Permian or Triassic in age based on palynomorphs, and we have found in all of our sections, including the site in question, that the [fungal spike containing] Katburg Formation begins well above the top of the Permian.

http://www.sciencemag.org/cgi/content/full/307/5710/709

http://palaios.geoscienceworld.org/cgi/content/full/19/4/418: a relationship between the fungal spike and an impact event has not yet been demonstrated at the P–Tr boundary.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VJ1-4PTN8MM-2&_user=1495569&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000053194&_version=1&_urlVersion=0&_userid=1495569&md5=f3c6ef0ccaff9f90f0ade951410e93e9 The proliferation of Reduviasporonites spores at the PTB in Europe [31] and [32] and South Africa [33] was initially interpreted as a spike in saprotrophic fungal activity after the loss of woody forests [31]. Together with evidence for pocket-rot cavities in fossil wood [26] and a loss of once-dominant woody conifer pollen [11], this fungal proliferation seemed to support the scenario of extensive forest loss at the extinction boundary [31]. This interpretation has been called into doubt given recent morphological and geochemical analyses indicating that Reduviasporonites is more likely to be of algal rather than of fungal origin [34]. A worldwide algal pulse suggests widespread PTB anoxia and generally stressed environments rather than increased fungal breakdown of woody tissues. However, cases of extensive (12 000 km2) regional die-off of modern forest dominants such as pinyon pine due to environmental stress from drought and bark beetle infestation [35] indicate that the massive loss of PTB forests may not be an unrealistic scenario (Table 2).

?http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6R-4GR8RWF-5&_user=1495569&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000053194&_version=1&_urlVersion=0&_userid=1495569&md5=537a1a5b0a8e04cca2221ecb12afb1e9# The difficulties encountered when attempting to determine the age of the PTB in continental sediments are well-known. Based on palynological data, Díez and co-authors update current knowledge on locating the PTB in the different Spanish basins. In spite of the scarce number of useful palynostratigraphical assemblages, they define time intervals for the succession of sediments of the Buntsandstein facies. Also through quantitative analysis of palynostratigraphical assemblages and exploring vegetation dynamics, Diéguez and Barrón describe drastic evolutionary changes in a 40 m thick interval of the Landete section, in the Iberian Ranges. These changes serve to infer the timing and scenario of the biotic crisis in Upper Permian sediments. The authors consider that the so-called end-Permian “fungal-spike” cannot at present be demonstrated in this area. This fungal event is also discussed in Diéguez and López-Gómez, who identified fungus–plant interactions in an exceptionally well-preserved Dadoxylon sp. trunk in the same section.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6R-4H8FR5H-1&_user=1495569&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000053194&_version=1&_urlVersion=0&_userid=1495569&md5=33921e4859ec8523b95d4ef909d29883 It is worth noting the scarcity or lack of fungal remains which indicates that in this area the “fungal-spike” event cannot be demonstrated.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VJ1-48HY72J-1&_user=1495569&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000053194&_version=1&_urlVersion=0&_userid=1495569&md5=d5013a2539e42592e510691cda855032 And links therein. This interpretation is not accepted universally. Some authors question whether the fungi were truly terrestrial because they are encountered only in shallow marine deposits [47]. Others have suggested that the apparent abundance of fungi could be an artefact of preservation because fungal hyphae are tougher than other plant tissues and are likely to survive longer in the environment [20]. Looy and colleagues [7] failed to detect a fungal spike
 * 20. D.H. Erwin. The Great Paleozoic Crisis: Life and Death in the Permian, Columbia University Press (1993).
 * 47 = 47. P.B. Wignall et al., The timing of palaeoenvironmental changes at the Permo–Triassic (P/Tr) boundary using conodont biostratigraphy. Hist. Biol. 12 (1996), pp. 39–62. View Record in Scopus |

http://intl-bulletin.geoscienceworld.org/cgi/content/full/115/9/1133 Conclusive one by Retallack Unfortunately, there are several fungal spikes at and above the boundary, so these spikes locate the boundary within only a few tens of meters. Furthermore, many palynomorphs identified as fungal hyphae may have been zygnematalean algae, indicative of lakes rather than an earliest Triassic zone of death and decay