One thing I must mention, is that security is very tight in the canal, much more so near the construction sites. So that day, we only had about 20 minutes to look at the fossil and eventually come up with a plan to collect it at some later time, if it was worth it.
And it was! Upon seeing the fossil, I immediately recognized it as a baleen whale jaw. Most of what we could see was a cross section of it (see below), which meant that however long the jaw was, it was going straight into the wall.
|Part of a baleen whale jaw, in cross section.|
The new whale mandible was found in the Gatun Formation of late Miocene (12-8 Ma) age (Collins et al., 1996). The Gatun is better known for the abundance of invertebrates (e.g. Woodring, 1957; Hendy, 2013) and for having deposits that represent nursery sites for Carcharocles megalodon (Pimiento et al., 2010). Previous reports of whales from the Gatun include odontocete ribs (Uhen et al., 2010), so finding a baleen whale is a first!
Like I mentioned above, that day we only had a very limited amount of time, and the fossil was worth rescuing. And so it was that over the next month or so I began coordinating with the Panama Canal Authority to go back and collect the fossil. Just last week we were able to go back. This time I had a new group of interns, and over the course of two days we were able to collect the fossil.
|The summer interns at the dig site. Chris (at far left) prospects, while Christina and Silvia dig around the whale jaw. You can see the construction of the new locks in the background.|
|The whale jaw, prior to being jacketed.|
|Me posing with the now jacketed whale jaw fragment.|
The exact affinities of the whale jaw remain a mystery, for now. Hopefully once it is prepared I'll be able to determine what it is. So stay tuned!
Collins, L. S., A. G. Coates, W. A. Berggren, M.-P. Aubry, and J. Zhang. 1996. The late Miocene Panama isthmian strait. Geology 24:687-690.
Hendy, A. J. W. 2013. Spatial and stratigraphic variation of marine paleoenvironments in the middle-upper Miocene Gatun Formation, Isthmus of Panama. Palaios 28:210-227.
Pimiento, C., D. J. Ehret, B. J. MacFadden, and G. Hubbell. 2010. Ancient nursery area for the extinct giant shark Megalodon from the Miocene of Panama. PLoS ONE 5(5):e10552.
Uhen, M. D., A. G. Coates, C. A. Jaramillo, C. Montes, C. Pimiento, A. Rincón, N. Strong, and J. Velez-Juarbe. 2010. Marine mammals from the Miocene of Panama. Journal of South American Earth Sciences 30:167-175.
Woodring, W. P. 1957. Geology and paleontology of Canal Zone and adjoining parts of Panama. Geology and description of Tertiary mollusks (gastropods: Trochidae to Turritellidae). U.S. Geological Survey Professional Paper 306-A:1-146.