Florissant fossils

One of the many pleasures of my visit to Yale last month was a visit to the collections of the Yale Peabody Museum. Among its treasures, the museum holds many of the fossils that were collected in the early 1900s from Florissant, Colorado.

The Florissant site is famous for its beautifully preserved plant and insect fossils, remains of the flora and fauna of the late Eocene, about 34 million years ago. In those good ol’ days, the climate was warmer and wetter, so a rich temperate forest grew in what is now a mix of dry, open grassland and ponderosa pine (replete with modern mammals, as I learned during my visit to the site last summer).

Most of the fossils are preserved in the finely laminate shale. Some of these laminae represent one year’s deposition: a layer of diatoms from the summer, overlain with ashy clay in the winter. These are interspersed with coarser material from rivers and landslides.

Division of Paleobotany, YPM 30074. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

Division of Paleobotany, YPM 30074. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved. The whole section depicted here is about 5 mm deep.

Many of the animals from the Florissant fossil beds look familiar to us, an indication of the continuity of taxa and their ecological roles across tens of millions of years.

Tethneus twenhofeli (orb-weaving spider). Collected by W. H. Twenhofel, date unknown. Described by A. Petrunkevitch, 1922. (Division of Invertebrate Paleontology, YPM 25588. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.)

Tethneus twenhofeli (orb-weaving spider). Collected by W. H. Twenhofel, date unknown. Described by A. Petrunkevitch, 1922. (Division of Invertebrate Paleontology, YPM 25588. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.)

Cranefly. Collected by J. T. Gregory, 1953. (Division of Invertebrate Paleontology, YPM 50208. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.)

Cranefly. Collected by J. T. Gregory, 1953. (Division of Invertebrate Paleontology, YPM 50208. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.)

The flora likewise contains many familiar taxa — redwoods, poplars, pines, hickories — but it also contains some enigmatic extinct species. One such puzzle is Fagopsis longifolia, a tree that may belong to the Fagaceae. If this interpretation is correct, Fagopsis is  kin to the modern oaks and beeches.

The following remarkable fossil shows Fagopsis with attached leaves and a fluffy ball of staminate inflorescences (i.e, the “male flowers,” bearing the stamens that produce pollen).

Fagopsis longifolia. Division of Paleobotany, YPM 30249. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

Fagopsis longifolia. Division of Paleobotany, YPM 30249. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

The separate pistillate inflorescence (the “female flower”) is also beautifully preserved.

Fagopsis longifolia. Division of Paleobotany, YPM 30121. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

Fagopsis longifolia. Division of Paleobotany, YPM 30121. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

Here is a close-up of the same specimen, showing the details of the long styles.

Fagopsis longifolia. Division of Paleobotany, YPM 30121. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

Fagopsis longifolia. Division of Paleobotany, YPM 30121. Copyright 2014, Peabody Museum of Natural History, Yale University, New Haven, CT. All rights reserved.

The most comprehensive treatment of the Fagopsis is Manchester and Crane‘s analysis of the leaves, flowers, fruits, and pollen of the species. It was therefore a privilege to examine the fossils with Peter Crane and to learn that the species still presents something of a puzzle, not fitting neatly into any modern group.

My thanks to Peter Crane, Shusheng Hu, Susan Butts, Derek Briggs, and Rick Prum for their welcome and assistance at the Museum. If you’re in New Haven, I strongly recommend a visit to the museum.

16 thoughts on “Florissant fossils

    1. David George Haskell Post author

      We have a few carboniferous plant remains poking out of the sandstone and some crinoids in the limestone, but nothing like Florissant. In upstate NY, we lived on a shale cliff that was oozing with Devonian life. Wonderful!

      Reply
  1. Paula

    Beautiful photos of the fossils…the detail preserved is amazing! I had the pleasure of working at the Peabody during grad school, first as a volunteer and then for real money, but with the anthropology and archaeology collections.

    Reply
  2. Henry Robison

    David:

    These are fascinating fossil photographs! I have visited Florissant, CO and seen where they come from. How did you take the photos? Camera type? Flash? I am doing a book currently on the Natural History of Arkansas and I will be including fossil photos. Yours are so outstanding, I thought I would ask your technique? Thanks for any comments you can provide Dave.

    Thanks,

    Rob

    Reply
    1. David George Haskell Post author

      Hi Rob, I’m delighted that you enjoyed the photos. I have no special method. I took the invert photos with a hand-held camera under fluorescent lights. The plants I took on a photo stand — camera screwed into the stand, pointing down at surface below, four incandescent bulbs shining from four corners. The fossils rested on sand. Those incandescent bulbs are a problem — they give an orange glow — so I did a quick-and-dirty filter in photoshop to cool the photos down and restore some semblance of “real” color balance. My camera is a Panasonic DMC-FZ200. It does not auto-correct color balance at all well, but has great close focus. One day I’ll learn to use its bells and whistles correctly.

      Reply
  3. Sabine

    Wow, that is stunning. Unfortunately I am in Germany, too far away for your museum. I live close to the famous site where Archeopteryx was found though (Eichstätt), a little consolation at last!
    I am an archeologist and esprecially the close up of the female flower looks a bit like a Roman wall painting!

    Reply

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s