An Ordovician ancestor to spiders

On this Memorial Day, I’m going to have to have a discussion with my spiders about their distinguished, noble ancestry. It was kind of Nature to publish a study of their many-times-great grand uncles, an ancient euchelicerate named Setapedites abundantis, a common fossil found in Moroccan sediments that are about 478 million years old, which puts it right in the middle of the Great Ordovician Biodiversification Event, a key moment in the evolution of modern taxa.

This is not a spider, though. It belongs in the euchelicerata, the large systematic group that includes spiders, scorpions, ticks, horseshoe crabs, sea scorpions, and other extinct groups. As you might guess from the name, a key feature is the presence of chelicerae, anterior appendages that in spiders carry the venomous fangs. It also has a common feature we see in both spiders and horseshoe crabs, the fusion of the anterior segments to form a prosoma, with posterior segments forming the abdomen or opisthosoma.

While it’s a cool looking little dude, it’s marine and pretty remote from modern chelicerates. From the dorsal side, it looks like an undistinguished little crustacean, of a type that was probably swarming in Ordovician seas.

A, B MGL.102899 and interpretative drawing, articulated specimen in dorsal view. C, D MGL.102828 and interpretative drawing, articulated specimen in dorsal view. E, F MGL. 102872 and interpretative drawing, articulated specimen in dorsal view. Abbreviations: btg, bipartite tergites; mr, median ridge; pl, pleura; pr, prosomal rim; saxn, sub-axial node; sr, sunken region; t1–11, tergites 1–11; t, telson; tk, telson keel. Scale bars, (A–F) 1 mm.

Where it gets interesting is when it’s flipped over, and you get a glimpse of the mass of limbs.

A, B YPM IP 517932c and interpretative drawing (counterpart), articulated specimen in ventral view. C, D YPM IP 517932c and interpretative drawing, chelicerae, and labrum anatomy detail. E, F Close-up of the prosoma of MGL.102934 and interpretative drawing, in dorso-lateral view. G, H Close-up of the prosoma of MGL.102634 and interpretative drawing, in ventral view. I, J Close-up of the prosoma of MGL.102800a under alcohol and polarized lighting, and interpretative drawing, in ventral view. Abbreviations: 1–6, podomeres 1–6 of the exopod; ptp, pretelsonic process; bs, basipodite; bst, brush-like setae; che, chelate podomere; db, doublure; lb, labrum; ss, single setae; st, pair of setae. Chelicerae are highlighted in gray, endopods in blue, exopods in green, opisthosomal appendages in red, and the pretelsonic process in purple. Scale bars, (A, B) 1 mm; (C, D) 100 µm; (E–K) 500 µm.

In front of the jaws proper (labrum, lb) it has a pair of small chelicerae (che). These have since evolved into the massive, sharptoothed chompers you can see my tarantula using to turn a mealworm into macerated mush.

Setapedites wasn’t such a fierce predator. Here’s what it looked like.

Illustration by Elissa Sorojsrisom.

Cute, right? I don’t know why it’s drawn as a swimmer, though — with that anatomy, it looks more like a benthic organism.

The final bit of interesting information is that they mapped out the correspondences in the segmentation of this animal with other, similar fossils and the extant Xiphosurians.

Simplified extended majority rule tree of a Bayesian analysis chronogram of euchelicerate relationships, based on a matrix of 39 taxa and 114 discrete characters, showing the position of Setapedites abundantis within Offacolidae. Lineages extending after the Silurian are indicated with arrowheads. Schematic models of the body organization in Habelia, Setapedites abundantis, Dibasterium, Offacolus, and Xiphosurida illustrate the origin and early evolution of euchelicerate uniramous prosomal appendages and tagmosis. Roman numbers designate somites. Prosoma somites are highlighted in blue, pre-abdomen somites in yellow, abdomen somites in brown, and the possible anal pouch or post-ventral structure (pvs) in purple. Black dorsal lines indicate tergites and cephalotorax. Schematic model of Xiphosurida Offacolus, and Dibasterium from 45, Habelia

Also of note: Setapedites had biramous appendages, a feature that is mostly kind of lost in modern arthropods — the outer branch got adapted into gills and lungs and even wings.

I can’t help but notice that domestication and artificial selection turns wolves in little yapping Pomeranians, but natural selection turns shrimp into tarantulas.

WoRk??!?

Mary made me do hard manual labor today. She has some serviceberries she wanted planted in the back yard, so I had to help cut chickenwire and bend it to make a protective circle around them — we have lots of rabbits around here — and then we had to dig holes in the thick, glue-like, clayey soil in our backyard (which, I know, isn’t the best for these bushes). Look what it did to my shoes!

Unfortunately, these are my only shoes. We’re poor, and I was supposed to get a new pair for my birthday a few months ago, and we never had the energy to drive all the way to Cabela’s. I guess I’d better make the trip soon.

Also, I’ve got a blister on my right hand. I am not made for hard manual labor.

We did find something interesting, a Masked Hunter.

Now though, I have to lie down and recuperate.

How can a cartoon be so true?

Does this remind anyone else of a certain University of Chicago professor who was both outraged that anyone would refuse to pay racists and gender criticals to speak on campus, while also freaking out that students had strong opinions he disagreed with? It’s uncanny.

Although…the worst ones tend not to call themselves “conservative.” They’re “liberal” or “centrist” or “open-minded” while magically and unthinkingly aligning themselves with conservatives all the way down the line.

It shouldn’t take so long to recognize a fool

I’ve seen Terrence Howard in Crash and Red Tails and the first Iron Man (he wasn’t in any of the sequels, I wonder why?), and he was fine as an actor. It’s when he goes off script that you discover that he is totally nuts. Professor Dave explores some of his lunacy.

It’s 48 minutes long, but most of it is redundant — at his first attempt to explain that 1 x 1 = 2, or his redrawn periodic table, or his wacky 3-dimensional models of elements, it’s clear that he has lost the plot. And then the video gets into Howard’s 3 hour long interview with Joe Rogan, and it becomes clear that Rogan is just as ignorant and deluded and deranged and useless.

I’ve seen no more than a few minutes of Rogan in short excerpts, and knew from my first exposure that he was a fraud. Nowadays, when I see an account on social media that is trying to sell how smart he is, I insta-block that channel. I’d do the same with any mention of Howard, except that everyone sees how foolish he is, and he isn’t getting paid millions of dollars to babble for hours on Spotify every day.

Spiders blooming everywhere!

Mary spotted all these tiny yellow spiders all around the backyard. Apparently, a sac full of Araneinae hatched out in the last few days.

These are the equivalent of those kids’ show Minions. They’re all over, I can’t tell them apart, and they talk funny.

While I was out roaming in the yard, I spotted a few other familiar faces. This is Salticus scenicus, the zebra jumper. They were all over the walls.

Then there was this guy, Parasteatoda, who had caught a sowbug. It’s like having lobster for lunch.

So that’s what they’re afraid of

People have this absurd fear that fraternizing with different kinds of people will radically transform them in every way.

If you think that, allow me to reassure you: I’ve been friends with and talking to gay and trans people for decades now, and I’m still heterosexual. I’ve just become a liberal, socialist-leaning, humanist-atheist who always votes for the political party with the more tolerant, progressive policies. Nothing to be afraid of there.

They like me! They really like me!

I hit a wall yesterday. It was just one of my bad days, when I felt kind of useless, and worried about what was coming in the fall — I’ve got one week of instruction planned, out of 15 weeks in the semester, and I’m coming out of a semester in which I’d gotten all experimental and weird and tried some things that maybe the administration would not approve of, because I was tired of trying to wedge students into boxes all the time. I just wanted them to learn how to think and have a good conversation about a subject for a change, and not be fretting over points and grades!

So that’s been weighing on my mind, in addition to the usual stuff, like backaches and being tired and it’s been raining pretty much nonstop for the past week.

And then the student evaluations appeared in my mailbox. I put off opening that message, like I usually do, because I was dreading what they would say, like always. I bit the bullet this morning and opened it up, since I didn’t think anything would make me feel worse this week, anyway. Yikes…they liked the course!

I skipped over the numerical scores, because they were always useless (despite being the only thing the university will use to evaluate my work) and went straight to the comments section. Here, they’re answering the question, “What did the instructor do that most helped your learning?”

PZ structured the class such that we had a predictable workload each week, with a variety of class activities, which was useful. Lecture days on Mondays were nice and relatively easy at the start of the week, and small group discussions on Wednesdays and Fridays were always fun. The final presentation for the class was also valuable, as it gave us the opportunity to explore a topic from the class that we found particularly interesting in depth and share our discoveries with our classmates.

Had lecture on Monday’s and allowed students to help each other.

I appreciated that we did a lot of article discussions as well as chapter discussions. It was good to think over those chapters without being lectured at

Wittyness and Sarcasm were plentiful, 10/10 course

Discussion based on what we were learning

I liked the discussion questions because they went with the lectures really well

Yes! They saw what I was trying to do!

The next question was “What suggestions do you have for improving the course?”

Clearer expectations for final presentations or updates on participation grades throughout the semester would be appreciated, although PZ did assure us periodically that we were all doing well and that he had no concerns about our performance in class.

Maybe have slightly more background when discussing topics that students don’t tend to be strong in.

I wish some of the grading standards were more clear, and that there was a proper rubric for the presentations. I honestly have no clue if my presentation was even good or not because I didn’t have any guidelines to work with other than “15–20 minutes long and can be about whatever that’s relevant and also it can be whatever medium you like”

Get these college kids to talk more, they all look so nervous to have a hot take on microplastics.

It would be good if grades were updated more frequently

I like this course

Criticisms accepted. Next time I’ll try to outline my expectations more, and incorporate a few more metrics throughout the course. I may have gone too far in trying to avoid grade-chasing and point-tallying. I did appreciate the comment to “Get these college kids to talk more, they all look so nervous to have a hot take on microplastics,” because that’s exactly what I wanted, a class full of people eager to talk about eco-devo.

All right, I feel a little better today.

How to cure your manly depression

I’ve been depressed lately, and I turned to YouTube to find out why. Cody Johnston asks “Are Men OK?” and I thought maybe this would explain it all.

Unfortunately, the first half of the video is a lot of excerpts from the self-declared gurus of manliness, Jordan Peterson & Fresh&Fit & Bronze Age Pervert & Elon Musk & Andrew Tate & Sneako & William James & Charlie Kirk & Teddy Roosevelt & Patrick Bet-David & Josh Hawley & Ben Shapiro (I tried to take notes, but there were so many I probably missed a few) and they just made me more depressed. I don’t even listen to any of them — I think they’re all flaming morons — but the idea that people so stupid can be so wildly successful financially is discouraging. I don’t think my problems have anything to do with what those bozos claim, but is more about being reminded of my limitations as I grow older and seeing the possibility of retirement constantly receding away from me.

In the last half he talks about solutions, but mainly they’re about dismantling the patriarchy and shutting down the grifters, which doesn’t actually help me directly, but would probably have other benefits.