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Dave Rodland @daverodland.bsky.social · 5h

One, photodocumentation has progressed a lot since 1890. Glass plates ... shudder. It got done, mind, but the difference in digital photography over the past 20 years has been incredible.

To your previous point though ... you don't. And that's the point.

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Dave Rodland @daverodland.bsky.social · 5h

That requires staffing with someone who has actual qualifications in relevant fields in a program that serves human need rather than one serving the preconceptions of high school seniors or the whims of fashion amongst the administrators of academe.

Because faculty surrendered everything.

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Dave Rodland @daverodland.bsky.social · 5h

What has been happening to higher education for the past thirty years has been one bad idea followed by something worse.

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Dave Rodland @daverodland.bsky.social · 6h

Everyone is replacing min/chrys and petrology courses with one semester of "Earth Materials" if they haven't eliminated geology entirely. Somehow administrators have gotten the idea (probably from consultants) that geology is environmental science is conservation ecology.

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Dave Rodland @daverodland.bsky.social · 6h

I'm no spring chicken, but I have rarely worked at an institution with anyone else with anything like a background in invertebrate zoology or marine ecology. Anyone else with stratigraphy interests came from a petroleum exploration background.

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Dave Rodland @daverodland.bsky.social · 6h

Spoken like a naticid!

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Dave Rodland @daverodland.bsky.social · 6h

It knows about Ichthyostega. It knows the Deep Knowledge. Phalange counts are for mudsuckers.

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Dave Rodland @daverodland.bsky.social · 6h

Bear in mind that hiring decisions in a highly competitive market aren't made on the basis of candidate qualifications, but on internal dynamics that are opaque if not actively concealed from the applicants.

It's not you, it's them.

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Dave Rodland @daverodland.bsky.social · 6h

I still kind of regret not walking up to say hi the one time I saw Bob at a GSA meeting (over a decade ago). On the one hand, I didn't have any particular reason to do so ... but I didn't have any reason not to, and all we were doing was perusing posters anyway.

But yeah, Heresies held up.

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Dave Rodland @daverodland.bsky.social · 6h

Not pseudopunctae? Just original punctae what got cemented? Hmm.

I will note here that, woth rare exceptions, brachiopods suffer drilling predation rates around 1% (and have since the Paleozoic), compared to their juicier, more delicious compatriots in Bivalvia.

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Dave Rodland @daverodland.bsky.social · 7h

Ironically, true as far south as Los Angeles, at least back in the day. Getting to snow in the San Gabriels wasn't any harder than getting to a chain up pullout in the Cascades.

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Dave Rodland @daverodland.bsky.social · 19h

Galeamopus is just stupidly charismatic.

Paleo selfie with a bronze cast model of the head of Galeamopus, fleshed out with scales of various size.

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Dave Rodland @daverodland.bsky.social · 19h

Objects in selfie may be closer than they appear. ⚒️🦕🦖

Selfie with skeletons: one unemployed necromancer in lower ledt, overshadowed by a charismatic grinning Galeamopus occupying the right half. Between them, a juvenile ascribed to Diplodocus, with a large carnivorous Torvosaurus lurking in the background. Behind and above Torvosaurus, Pteranodon sternbergi, the one with the funky headgear. Upper left corner, peeking over the paleontologist's chrome dome, is Apatosaurus.

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Dave Rodland @daverodland.bsky.social · 19h

That brings us back to middle Ordovician origins, including Astraspis desiderata, Eriptychius americanus, and, of course ... Sacabambaspis!

Sacabambaspis (English Cover)「サカサカバンバンバスピスピス」【Will Stetson】

YouTube video by Will Stetson

youtu.be

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Dave Rodland @daverodland.bsky.social · 19h

It's actually not a new argument! Aglaspid affinities have been noted for decades, but the convergence on phosphatic exoskeletons was pretty convincing, and the most convincing evidence it wasn't the first armored fish only dropped this year. Haridy et al. 2025, for your consideration:

The origin of vertebrate teeth and evolution of sensory exoskeletons - Nature

Re-examination of the presumed Cambrian fossil fish Anatolepis reveals previous misidentification of aglaspidid sensory structures as dentine, a vertebrate sensory tissue, showing it to be an arthropod, and shifting the origin of vertebrate hard tissues to the Middle Ordovician.

share.google

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Dave Rodland @daverodland.bsky.social · 1d

Flip side: Ellie Sattler is and always was 100% the protagonist. Alan and Ian just kinda fumbled along, but she Got Shit Done.

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Dave Rodland @daverodland.bsky.social · 1d

These are among the oldest bony fish in the fossil record, since Anatolepis turned out to be a crustacean. Not ancestors, but the greatest gruncles and graunts of every living fish and tetrapod. There are so many questions left to resolve. Maybe I'll get back there someday.

This is auspicious.

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Dave Rodland @daverodland.bsky.social · 1d

I did my undergraduate thesis work tracking down Walcott's original sites (my cover photo is from Helena Canyon, the other reference section he described besides the Harding quarry). The Cincinnati Museum Center has this display noting their complete and inexplicable absence from the Cincinnatian.

Display at the Cincinnati Museum Center with two specimens from the Harding sandstone including dermal armor from Astraspis. Trust me, these aren't great examples; they have better in storage. I made damn sure of it.

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Dave Rodland @daverodland.bsky.social · 1d

Butterflies, I have discovered the most niche piece of marketing genius since, oh, let's say the Sandbian ... PRI quietly dropped a new Paleozoic Pal when I wasn't looking, and it's Astraspis desiderata!!!

Ok, this is the only place on the internet where anyone else is going to get excited.

Selfie with a stuffy: bald dude in glasses and a bright red shirt holding the most adorable piece of niche marketing Museum of the Earth / PRI has ever put out, a plush Astraspis desiderata!

Plushie with label:
"Paleozoic Pals
Jawless fish
(Astraspis desiderata)"
Astraspis is depicted as a large-eyed stuffed animal roughly 8" (20cm) long, with a cephalic shield composed of overlapping scales in various shades of blue, with olive drab ventral side. A bumpy blue dorsal ridge follows the
spine, with two more ridges parallel on either side.

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Dave Rodland @daverodland.bsky.social · 1d

About ten years back, I visited the Tennessee Aquarium and watched in astonishment as a sea star crawled slowly across the sand to high five a very annoyed cuttlefish. Full color threat display and everything, but it would not move until the tube feet touched arms.

Wish I'd taken video.

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Dave Rodland @daverodland.bsky.social · 1d

Oof! I only ever did those from slides. My Icelandic pronunciation is crap.

And I spent years trying to pronounce 'Popocatepetl' without dying.

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Dave Rodland @daverodland.bsky.social · 1d

The arthropod bauplan does suggest a hypothetical approach where excrement could be shed during successive molts. Any small ecdysozoan might do, honestly, although I can't imagine a reason that would be preferable. Articulate brachiopods are the only clade I know that decided anuses were overrated.

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Dave Rodland @daverodland.bsky.social · 2d

And then there's Osedax mucofloris, the bone-eating snot flower. Enjoy that rabbithole ...

Had I given the whalefall speech (and I salute her for doing so), this would've been a major tangent.

en.wikipedia.org/wiki/Osedax

Osedax - Wikipedia

en.wikipedia.org

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Dave Rodland @daverodland.bsky.social · 2d

That said: there's a whole slew of Precambrian "critters" (probably but not definitely animals), the Ediacaran biota, that lacked guts and are thought to have been passive nutrient absorbers.

Similarly, modern chemosymbionts like Riftia have given up digestion as a bad idea.

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Dave Rodland @daverodland.bsky.social · 2d

Most animals without a through-going gut regurgitate whatever they can't digest. Although biology being the collection of "hold my beer" that it is, someone will hopefully chime in with the example of an invert that never excretes solid waste, just collects it unto death.

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