Apocalypse past: coastal fungal assemblages following warming events

O'KEEFE, JENNIFER M.K.; ROMERO, INGRID C.; MAGGIE STEPHENSON; SPEARS, TYLER M.; NUÑEZ OTAÑO, NOELIA B.

Manizales

Congreso; 54th AASP Meeting - Manizales 2022; 2022

The palynological society

Fungal community response to warming events is of great interest to mycologists and paleoecologists as they seek to develop models to forecast future changes. Equally important, however, is how fungal communities respond to cooling conditions and whether those responses can be teased apart from response to changing depositional environments. Here we examine two different examples of fungal assemblages preserved in coastal sediments following warming events: those from the Carrizo Formation (Ypresian, Eocene, Texas) and those from the Upper Hattiesburg Formation (Serravallian-Tortonian, Miocene, Mississippi). The sand-dominated Carrizo Formation was deposited in a shallow marine setting, possibly a tidal delta, while the clay-dominated Upper Hattiesburg was deposited as a series of interfluvial overbank deposits adjacent to a coastal fluvial system. As such, the fossil fungal communities preserved in each setting are different, however, both record variations in fossil fungal assemblage upward. Preliminary interpretation of these results indicates that those assemblages in the Carrizo Formation record a transition from tropical to sub-tropical wet to sub-tropical less-wet conditions while those in the Hattiesburg Formation record a transition from warm, moist temperate conditions to drier temperate conditions.