A leafcutter bee trace fossil from the middle eocene of patagonia, Argentina, and a review of Megachilid (Hymenoptera) ichnology

The ichnospecies Phagophytichnus pseudocircus isp. nov. is described to include trace fossils characterized by leaf-margin excisions showing eccentricity values of 0.35-0.65 and more than 270 degrees of an arc, a non cuspate margin and vein stringers or necrotic flaps of tissue along the margin. A m...

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Bibliographic Details
Authors: Sarzetti, Laura Cristina, Labandeira, Conrad C., Genise, Jorge Fernando
Format: article
Status:Published version
Publication Date:2008
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/100644
Online Access:http://hdl.handle.net/11336/100644
Access Level:Open access
Keyword:ARGENTINA
LEAFCUTTER BEE
PATAGONIA
PLANT-INSECT ASSOCIATIONS
RÍO PICHILEUFÚ FLORA
TRACE FOSSIL
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Description
Summary:The ichnospecies Phagophytichnus pseudocircus isp. nov. is described to include trace fossils characterized by leaf-margin excisions showing eccentricity values of 0.35-0.65 and more than 270 degrees of an arc, a non cuspate margin and vein stringers or necrotic flaps of tissue along the margin. A method for determining ellipse eccentricity was performed on leaf discs obtained from the nests of the modern leafcutter bee Megachile rotundata (Hymenoptera: Megachilidae), which provided objectively obtained values comparable to the trace fossil from the middle Eocene of Argentina and other world-wide ichnological records, historically and subjectively considered to be 'circular' trace fossils and attributed to leafcutter bees. The material described herein represents the first evidence for fossil Megachilidae from the Southern Hemisphere.