Abstract Detail

Paleobotany

Herrera, Fabiany [1], Muller, Gregory [1], Huhndorf, Sabine [2], Soriano, Carmen [3], Manchester, Steven [4], Jaramillo, Carlos [5].

Exquisitely preserved xylariaceous fungal fruiting bodies from the Early Miocene of Panama.

The Xylariaceae are a diverse and cosmopolitan family of ascomycetous fungi with at least 76 genera, currently comprising more than 1300 species. The group is most diverse in tropical to sub-tropical wet environments, but many species are found in temperate regions. Fungi of this group are important wood-degraders and many species are commonly found with conspicuous stromata on standing dead tree trunks or fallen logs. Although fruiting bodies of Xylariaceae are relatively common in present-day wet environments, stromata fossils are extremely rare. Cretaceous to Quaternary ascospores of Hypoxylonites, which are characterized by an elongate germ slit that parallels the long axis have been commonly associated to several Xylariaceae genera. Here, we report exquisitely preserved and abundant permineralized fruiting bodies attributable to Xylariaceae from the Early Miocene, Cucaracha Formation of Panama (~19 million years old). The fossils are preserved as calcareous cellular permineralizations in poorly sorted volcaniclastic sandstones. Several fossil stromata were cut longitudinally and then serially sectioned using the cellulose acetate peel technique. Acetate peels were mounted in Canada balsam or analyzed under scanning electron microscopy. Fruiting bodies were also studied by X-ray propagation phase contrast tomography (PPCµCT). At least two morphotypes are recognized. One of them is characterized by a spherical to hemispherical stromata, containing abundant perithecia with conspicuous perithecial mounds, perithecia spherical-wide to obovoid, ostioles encircled with a disc, ascospores unicellular and ellipsoidal with a straight germ slit on the dorsal side. The second morphotype is characterized by applanate stromata, with perithecia immersed, perithecia narrow, more or less elliptical and tightly packed. The fossil fungi are found together with a rich and diverse carpo- and wood- flora, mostly composed of Neotropical angiosperm taxa. Many of the fruiting bodies are found attached to permineralized angiosperm wood and log remains suggesting saprotrophic nutrition. The new Panamanian fossils represent one of the best opportunities to study the history of xylariaceous fungi in a Neotropical setting.

1 - Chicago Botanic Garden, Plant Science Center, 1000 Lake Cook Road, Glencoe, Il, 60022, USA
2 - Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, Il, 60605, USA
3 - Argonne National Laboratory, 4X-ray Science Division, Advanced Photon Source, Argonne, Il, 60439, USA
4 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611, USA
5 - Smithsonian Tropical Reserach Institute, Ancon, Panama

Keywords:
fungi
Xylariaceae
ascomycetous 
fossil
Miocene
Panama.

Presentation Type: Oral Paper
Session: 28, Mesozoic to Pleistocene Paleobotany
Location: 102/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 4:15 PM
Number: 28011
Abstract ID:682
Candidate for Awards:None