Mesozoic

You're listening to Love in the Time of Chasmosaurs, the podcast, the audio supplement to our blog of the same name about the art, science and popular culture of mostly Mesozoic life.

I'm Nutty.

I'm Mark.

In many ways, it felt to me like a kind of an immersive illustrated book, if you will.

We know, of course, that there were re-edited sequences from Apple TV's Prehistoric Planet, which are projected onto the walls of the show space in 360 degrees, and in most cases at life-size, so that you could, for example, feel yourself at the feet of Dreadnoughtus as they walked through.

And these weren't done at random as a kind of montage, but the sequences were organized under sort of mini chapter headings of sorts about the Mesozoic world.

whilst recalling parallels with the extant wildlife of the modern one and how they inform how we reconstruct the animals of the past.

And these re-edited sequences from the show were interspersed with other images, photographs, illustrations, CG sequences, which apparently were bespoke for the display.

but on the latter point he wisely held that quote it would be manifestly absurd to introduce into a newly studied province the nomenclature which had been adopted in those provinces previously studied in quote uinta page thirty eight this principle guided him some years later when he pointed out in his first report as director of the united states geological survey that the introduction of local formation names has taken place in opposition to received opinions and in spite of the almost universal efforts of geologists to attain uniformity it therefore represents the logical and necessary growth of the science End quote.

Powell was one of the pioneers in the demonstration of the almost undisturbed continuity of deposition in the West from the Cambrian to Tertiary time, sometimes slightly interrupted by gentle unconformities, but without trace of the revolution that, from the structures known in Europe and eastern North America, had been previously supposed to mark a worldwide break between the depositional records of Paleozoic and Mesozoic times.

he was the first to bring out the great structural features of the plateau province already referred to he repeatedly emphasized the action of uplifting rather than of compressing forces for he had chiefly to do with broad structures of nearly horizontal strata limited by faults or as he so justly remarks their homologues monoclinal flexures and the latter style of deformation was in his time a geological novelty complicated deformation was mostly limited in the plateau region to zones of diverse displacement between extended areas of little disturbance the only sharp folds with which he had to do occurred in these narrow zones he suggested that flexing of strata was probably a deep-seated process while faulting was a more superficial one as in his discussion of the problem of antecedents stated above so through all his writings he strongly supported the then growing idea that upheaval was not marked by a great convulsion for the lifting of the rocks in the uintas was so slow that the rains removed the sandstones almost as fast as they came up Following his systematic habit of mind, he grouped the mountainous reliefs of his region into two great classes.

Some were composed of sedimentary strata and others of extravasated materials.

But Powell is much more thoroughgoing and definite than any of his predecessors.

He states in his second report, after recognizing the rapid wearing down of Highlands, quote, the degradation of the last few inches of a broad area of land above the level of the sea would require a longer time than all the thousands of feet which might have been above it so far as this degradation depends on mechanical processes but here the disintegration by solution and the transportation of the material by the agency of fluidity come in to assist the slow processes of mechanical degradation and finally perform the chief part of the task u one ninety six this passage is of special interest as being the most explicit statement made by powell regarding the general possibility that normal erosional processes working on a land mass long undisturbed will ultimately reduce the whole surface to a low land but little above sea level End of section 9.

X. PLANATION these general results were not left without practical application the great plains of erosion revealed by the superb unconformities in the bottom of the grand canyon of the colorado in northern arizona were evidently regarded as the result of persistent erosion by rain and rivers during prolonged still stands of the region in ancient geological periods but the phraseology adopted for the peroration in which the history of these buried lands is set forth must leave the uninformed reader in some doubt as to the precise nature of the facts and inferences there presented a simpler statement is given for the plateau like highlands of crystalline schists flanked by upturned sedimentaries in the colorado front range which has made a deep impression on powell when he crossed them in his first western journey in eighteen sixty seven he afterward recalls that he had then dimly conjectured that tens of thousands of feet had been eroded from some of the ranges and that the table or plateau like character of the ranges was due to some epoch of this later denudation of the ranges when they were planed down to a common level such a planing down occurs when the channels of the eroding streams remain for a great length of time at a general base level you into page twenty seven it would thus appear that the first observer to recognize this fundamental process in the origin of the front range of the rocky mountains was not marvin to whom it has elsewhere been credited but powell true he does not explicitly state that the plain down surface of the front range was afterward broadly uplifted to its present highland altitude in order to excite its streams to erode the gorges by which it is now dissected but no one who reads his reports can doubt that he understood the uplift as clearly as the planing down following the principles so well and so early applied in colorado he afterward perceived that the ranges of the great basin though composed of ezoic and paleozoic rocks are mountains of very late upheaval, and that before upheaval their region was, quote, a comparatively low plain, constituting a general base level of erosion, to which that region had been denuded in Mesozoic and early Tertiary time, when it was an area of dry land.

He was thus led to say, Mountains cannot long remain as mountains.

So, like, here's a little part from Europe, you know, and here's a little part from Asia, and you see this.

And then r- in Tropical Americas, uh, you'll see that there's a little part that sticks out, uh, that is like a, like a, um, Mesozoic temple.

Um, and that's not, it, with a monkey on it.

That's not in Animal Kingdom yet, but Joe Rohde was trying desperately to manifest it.

You have to have just the right conditions to fossilize them.

So actually, all the fossil sites that have those just-right conditions that are showing us what feathers were like in the Mesozoic, they're almost all from the Early Cretaceous.

Our understanding of feathers in the Late Cretaceous is extremely limited.

So you know, the Hell Creek is one of the best known, you know, fossil-bearing geologic units in the world, right? You know, it's where T.

How well-preserved is this feather?

It's pretty darn perfect.

Like, uh, it's, it's the best preserved feather from the Mesozoic.

The previous best feathers were all preserved in, in amber, but in amber you still get, uh, some distortion in the, in the resin, so, you know, you're not able to, uh, see certain very fine detailed features.