Part II of The Evolution of Reptiles; early mammals (October 29 – November 2)

This week we will continue with dinosaurs, so please see the links and prose from last week. We will then explore the development of flying vertebrates, emphasizing pterosaurs. Remember that we have no classes on November 5 and 7 because I am at a meeting of the Geological Society of America in Indianapolis. We may thus start working ahead in lectures this week.

Mammals evolved so gradually from the reptiles that it becomes difficult to say when the first mammal appeared. (A familiar story that you’ve heard with the fish, amphibians, dinosaurs, and “birds”.) The Wikipedia page on the evolution of mammals is quite good, and the related page on the cynodonts (a type of therapsid which includes the mammal ancestors) is useful. We will talk in detail about the various innovations which characterize the mammal-like reptiles and the early mammals. (And we won’t use all the terms in these pages, of course.)

Your second test will be on Friday, November 2. Our review session is on Thursday, November 1, 3:30 – 4:30 p.m. Here are the Fall 2017 second test answers for your study. Your test, of course, will be different. Those student answers are not optimum, just good enough for full credit. As with all sample tests, our current class has covered somewhat different material. Test seating: Students with last names starting with M through Z in Room 205 (our regular room); A-L in Room 216 (across the lobby). Test doors open at 7:50 a.m.; all tests due at 8:50 a.m.

Here again is our Classification of the Phylum Chordata used in this course. It is a list edited just for you. Yes, you do need to know all these names.

Gigandipus, a dinosaur footprint in the Lower Jurassic Moenave Formation at the St. George Dinosaur Discovery Site at Johnson Farm, southwestern Utah.

Geology in the News –

Climate change is producing an insect apocalypse. Many ecosystems have experienced a profound loss of insect diversity and abundance over the past decades. As budding ecologists you know this has many serious knock-on effects, including loss of pollinators and insectivores. My treasured Joshua trees of the Mojave Desert are dying out because their pollinating moths are disappearing.

We’ve known that the Earth’s inner core is solid from calculations and formulae, but now we have direct evidence of its nature. Solid but a bit squishy. And really hot.

Chemists have found a recipe to build all four nucleotides of RNA in a way that could have happened on the surface of the early Earth. This is a biological breakthrough that could show a theoretical pathway to the RNA World. Very cool.

I’ve given you so much bad news this semester about climate change (and we know plenty of other anxieties going on now too!) that you need a set of charts and maps with how much better we have it than our ancestors.

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