Yesterday, we left Santiago mid-morning, and took the Panamerican highway north. We crossed scrubland and farms distributed on the outlying areas of Santiago. Along the road, we picked up some much needed fruit, by the sackful. There's nothing like hucking 20 lbs of citrus into the field truck. And the avocados (palta) are just perfect.
Picking up fruit along the road, CSG and NDP. (Photo JF Parham)
Based on a good tip from lab member Jorge Velez-Juarbe, we decided to take a short detour on our trip north to the small town of Puerto Aldea, about 50 km south of Coquimbo. Being naturalists, we were excited to hear that the Chilean coast, in some isolated pockets, harbors seagrasses. These communities, which are maximally rich in the Gulf of Mexico, are distributed around the world in temperate and tropical latitudes -- but they are nearly absent from the entirety of the Pacific coast of South America. Seagrasses are interesting for a variety of reasons to marine vertebrate enthusiasts (i.e., they are consumed by turtles and sirenians); their fossil record is also notoriously sparse. It is also likely the seagrass communities supported many extinct marine mammals, such as desmostylians and aquatic sloths, the latter of which were recently recovered from the Bahia Inglesa Formation.
Along the road to Puerto Aldera. (Photo JF Parham)
Over Gchat, Jorge quickly reminded me about the supposed lost seagrass tribe of the Pacific coast of Chile, and after some quick research, we discovered that it wasn't too much of a detour from our planned stop in La Serena. The drive was mostly on dirt road, but the views were spectacular -- completely reminscent of the northern California coast on which Jim and I had spent much of our grad school years. Once we got into the small town (passing by outcrops of the late Miocene Coquimbo Formation, along the way), we flagged down a fisherman -- and to our delight, seagrasses were right on the shore.
A view of the Miocene; seagrasses at Puerto Aldera, Chile. (Photo JF Parham)
The little we know about these seagrasses here (and also at Concepción, according to the fisherman), suggests that they are a relict from a previous distribution that was much more widespread. We also know that between the end of the Miocene and through the Pliocene, the coast of Chile and Peru was inhabited by several marine herbivores, indicating that the seagrass communities to support them were also around at the time. The current thinking is that the late Neogene shore of Chile and Peru didn't look too different from today (i.e., adjacent to an arid desert). So, it's not too much of a stretch to say that this is a view of the Miocene -- sans the bony-toothed birds and aquatic sloths.