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Bee fossil explains Ice Age environment in Los Angeles

This is a comparison of (A) a modern leafcutter bee pupa in a nest cell to (B) a micro CT scan reconstruction of a 23-40,000 year old leafcutter bee pupa.
Images by Harold Ikerd, USDA-ARS Pollinating Insect Research Unit at Utah State University (modern pupa) and Justin Hall, Dinosaur Hall, Natural History Museum of Los Angeles County (CT scan reconstruction and figure). Usage Restrictions: None

A CT scan analysis of the nest structure and anatomy of a fossil leafcutter bee nest cells containing pupae from the La Brea Tar Pits conducted by Anna R. Holden of the Natural History Museum of Los Angeles County, bee specialists Jon B. Koch and Dr. Terry Griswold from Utah State University, paleobotanist Dr. Diane M. Erwin from the University of California Berkeley, and Justin Hall from the Natural History Museum of Los Angeles County explains the environment in the Los Angeles area during and after the last Ice Age according to the authors report in the April 9, 2014, edition of the journal Public Library of Science.

Leafcutter bees (Megachile gentilis) lived in the area around the La Brea Tar Pits for the last 40,000 to 50,000 years.

The anatomical examination conducted by the researchers indicates the bees have changed very little since the Late Pleistocene.

The examination of the nest and the materials the nest was composed of indicates that ancient leafcutter bees preferred a moderately moist climate and inhabited lower elevations during the Late Pleistocene. The leaves that composed the cells in which the bee pupae developed were traced to a region near the nest site that probably was near a lake or river.

This is one of the few exacting examinations of insects recovered from the La Brea Tar Pits and is indicative of the wealth of information stored in insect fossils.