Phytosaurs the Ultimate Keepers of Geologic Time
Phytosaurs as Timekeeper!
“Mah-Kair-uh-pro-soap-us” trips me up almost every time! It isn’t “macha” like the drink 🤣
#Phytosaurs are used to determine where one is at stratigraphically (aka when in time) in the Southwest. Dubbed index fossils, they are handy references, providing you find the right parts to ID them. Most index fossils are invertebrates because they are plentiful and found complete (usually), making them easier to ID.
One can see they are very different looking skulls, here stacked from most recent to oldest i#.
#Redondasaurus ~206 mya (Rhaetian)
#Machaeroposopus ~210 mya (Norian)
#Angistorhinus ~225 mya (Carnian)
You can see videos of Angistorhinus and Machaeroprosopus (=Pseudopalatus) if you scroll a few videos back.
Redondasaurus hasn’t been seen here in awhile. It is arguably the youngest of the phytosaurs, certainly quite derived in the supratemproal region. Enough specimens have been found to identify potential sexual dimorphism.
Convergent evolution is wonderful. Vertebrates again and again end up with long, thin snouts to snap up fish. Long jaws snap shut really fast.
Phytosaur noses are not at the tip of their snout, like #ghavials, #crocs, and #alligators today, but instead in front of their eyes. I’ll bet it was safer than having unhappy-to-be-eaten prey thrashing near one’s snout.
Notice the differences in snout length, skull length, and skull height. Though all here are related, they were each doing something different food-wise.
These animals are as long, or longer, than modern #crocodiles, and were the heaviest, most powerful predators of their day.
There is some debate over what genus name to use for Redonda. Plenty of room for future phytosaur research!
Born and raised in the Southwest, trying to wrap my head around the fact it was a massive swampy area, with lots of streams and lakes, loaded with #cycads and #ferns, #conifers and numerous #plants that no longer exist, it leads to wonderment. That the high desert was a swampy environ where phytosaurs and numerous other creatures thrived, dominating the landscape, keeping #dinosaurs in their unrightful place, is amazing and awesome!
#FossilCrates