“Fossils of the Night – The History of Bats Through Time” is a new YouTube video (53 minutes) brought to you by Dr. Gregg Gunnell from Duke University, speaking in the Royal Tyrrell Museum series on prehistoric topics.
Dr. Gunnell reports:
- only one extinct genus of fruit bat/flying fox
- 40+ extinct microbats (all echo-locators)
- Bats not close to primates, but with carnivores, hooved mammals, etc. (pretty broad!)
- Origin to 65 mya according to molecular clock
- Appear at 52 mya. We lack bat fossils from the Paleocene
- 11 extinct families of bats
- Icaraonycteris and Onychonycteris are two of the oldest known fossil bats. (Eocene, 52 mya) complete
- Messel bats (48 mya) more or less complete.
- More recent bats are bits and pieces, mostly dental taxa
- None of these are directly related to living families
- By the Pliocene nearly all modern taxa are known from fossils.
- Brachial index (forelimb/hindlimb ratio) midway between non-volant and flying mammals.
- CT scans of the teeth were made. All the inner halves of the teeth are crushed into small pieces.
- Certain lacewings, both extinct and extant, have a auditory organ on the wings that enables them to detect bat sonar. They stop flying when bats are detected.
- Bats have a low metabolism for their size. They live for up to 40 years.
- Smaller size increases wingbeat and sonar frequencies
- ‘Phyletic nanism’ describes body size decrease, island dwarfism. Onychonycteris was 38-40g. Microbats run about 14g.
- Gunnell reports on Yi qi, accepting the patagium/extra wrist bone hypothesis, which was falsified here.
- The origin of bats — Dr. Gunnell reports we don’t know what came before Onychonycteris.
- Nice morph video (5 seconds) of an inverted mammal on a tree trunk turning into a bat at the very end of the presentation.
This origin agrees with the large reptile tree,
which pulls both bats and primates out of carnivores. Here (Fig. 1) the extant Ptilocercus is employed as a model bat ancestor morphotype.