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[Abstract:]

#41

Science / Re: Tyrannosaurids and Other B...

Last post by Recusant - July 14, 2026, 05:43:06 PM

This one is pretty cool. Based on reexamination of fossils of small dinosaurs, it appears that Tyrannosaurus rex laid large clutches of relatively small eggs rather than smaller clutches of larger eggs--a revision of the hypothesis regarding their reproductive strategy.

"'Vanishingly Rare' Discovery: T. Rex Hatchlings Were Smaller Than a Cat And Born by The Dozen" | ScienceAlert

Jurassic Park was wrong. Again.

In the second movie, hunters find an infant Tyrannosaurus rex and use it to lure the adults into a trap.

But in reality, that baby would have been much smaller, about the size of a cat. And it probably wouldn't have been alone – the nest may have been absolutely crawling with dozens of them.

It likely wouldn't have been very useful as bait either: Its parents probably would have considered losing a baby or two as just part of the process, and wouldn't have cared enough to push a research trailer off a cliff.

So why are we updating our understanding of T. rex's childhood?

In a "vanishingly rare" discovery, paleontologists have found and closely examined fossils of tyrannosaur hatchlings. The remarkable findings are published in the journal Biology – and the implications go way beyond everyone's favorite dinosaur.

"Going through museum collections, my colleagues and I have discovered the first remains of hatchling tyrannosaurs," announced Nick Longrich, paleontologist and evolutionary biologist at the University of Bath in the UK.

[. . .]

Longrich and his team set out to investigate these fragmented fossils gathering dust in storeroom drawers, expecting to find adult specimens of small dinosaurs. Instead, ironically, the work led the team back to the big guys.

One of the small bones appeared to be a third metatarsal – the middle foot bone – of a theropod dinosaur. But on closer inspection, it didn't look like it came from a fully grown animal.

"The surface of the bone was incredibly porous," Longrich says in a video on his YouTube channel.

"And this is the result of all these little microscopic blood vessels creating this dense network of blood vessels. And these nourish the bone as it grows. So they're providing blood to the bone cells as they deposit bone tissue and remodel the bone. And this is typical of an immature dinosaur."

When the bone was compared to others of its era, the researchers realized only one species fit the characteristics they were seeing.

"This is the foot bone of a very, very tiny T. rex. This is the smallest T. rex that we've ever seen," said Longrich.

After that find, the team began to look more closely at other small fossils of bones and teeth, and realized that many could also be attributed to tyrannosaur hatchlings.

[. . .]

The goal of reproduction is obviously to make more of yourself, and in a general sense, organisms use one of two broad strategies to get there.

They either have lots of offspring, quickly and often, so that it doesn't really matter if some (or most) of them don't live very long – there are plenty of backups. Organisms that use this method, such as rodents, are known as r-strategists.

The other method is to have fewer babies, but invest heavily in making sure they survive. These are the K-strategists, and that group includes whales and, of course, us.

[. . .]

[T]he new discovery that tyrannosaur young were small and numerous suggests they had more r-strategist tendencies than we thought.

[Continues . . .]

The paper is open access:

"Hatchlings of Tyrannosaurus rex and the Evolution of Dinosaur Reproductive Strategies" | Biology

Abstract:

Tyrannosaurs were giant predatory dinosaurs that occupied the apex of Late Cretaceous food chains. Little is known about the early life and reproductive ecology of tyrannosaurs due to the extreme rarity of hatchling and juvenile fossils.

We report bones of hatchlings (<1 yr) for Tyrannosaurus rex and Gorgosaurus libratus, weighing ~2.5 kg and ~2.4 kg, respectively, i.e., <0.1% of adult mass. Clutches were likely large. We conservatively estimate ~20 eggs in a small adult T. rex versus ~30 eggs in the largest T. rex, and clutches of ~15 eggs in G. libratus; larger clutches of 50 or even 100 eggs are not impossible.

This suggests an r-selected reproductive strategy. Synchrotron scans reveal Haversian bone remodeling, suggesting that tyrannosaurs moved soon after hatching. Hatchling tyrannosaurs' small size and precociality suggest limited parental care; teeth of hatchlings show wear suggesting that they fed on relatively large vertebrates.

Tyrannosaurs had proportionately larger offspring than most reptiles, but relatively smaller hatchlings than Eumaniraptora and birds, suggesting retention of a primitive reproductive strategy intermediate between that of basal diapsids and birds. Multiple dinosaur lineages evolved large eggs independently, suggesting an evolutionary trend towards increased parental investment.

#42

Laid Back Lounge / Re: Multi-Association Thread

Last post by billy rubin - July 13, 2026, 11:47:37 PM

#43

Laid Back Lounge / Re: Multi-Association Thread

Last post by Recusant - July 13, 2026, 07:24:00 AM

[Abstract:]

#44

Science / Re: Black Holes in the News

Last post by Recusant - July 13, 2026, 07:02:12 AM

Two items on black holes appeared in the pop science sites this past week.

"Black hole collisions may follow entropy law, offering simpler remnant predictions" | Phys.org

When two black holes orbit each other, they eventually spiral inward and collide in one of the most violent phenomena in the universe. The event is so energetic that it significantly distorts the universe around it. It emits gravitational waves—ripples in the fabric of spacetime—that are strong enough to be detected with precision instruments on Earth even when they originate billions of light-years away.

These gravitational waves carry information about the event that physicists use to predict the size of the merger's resulting new, larger black hole—referred to as a remnant. But accurate predictions involve complex equations originally developed by Einstein as part of his theory of general relativity that require supercomputers to solve.

Now, a team of researchers led by physicists at Penn State has shown that there may be a simpler way, which also points toward a deeper understanding of the physics contained in those complex equations.

"The final black hole after a merger is ringing like a struck bell, and it radiates away more gravitational waves until it settles into a calm, stable state described by just two numbers—its final mass and spin," said Monica Rincon-Ramirez, a postdoctoral scholar in physics in the Penn State Eberly College of Science and the first author of the paper.

"The question we asked is: Can we predict what that final state looks like using arguments from thermodynamics?"

[. . .]

The new work suggests that once the energy and angular momentum—a measure of the system's rotational motion—carried away by gravitational waves are properly accounted for, the final black hole appears to be the state that maximizes entropy, the measure of randomness in a system, tracking the natural tendency of the universe to go from a state of order to a state of chaos.

"Entropy is essentially a measure of disorder, or more precisely, of how many ways something can be arranged," said Vaishak Prasad, a postdoctoral researcher in astronomy and astrophysics at Penn State and an author of the paper.

"A messy room has high entropy—there are countless ways things can be strewn about. A perfectly tidy room has low entropy—there are only a few arrangements that count as 'tidy.' Nature tends to drift toward high-entropy states simply because there are more of them. Our results suggest that black hole mergers do something similar."

The team developed what they call the "maximum entropy conjecture for black hole mergers," which is strikingly similar to ordinary thermodynamics.

[Continues . . .]

The paper is behind a paywall.

Abstract:

The final state of a binary black hole merger is predicted with high precision by numerical relativity, but could there be a simple thermodynamic principle within general relativity that governs the selection of the remnant? Using post-Newtonian relations between the mass 𝑀 (including the binding energy) and angular momentum 𝐽 of quasicircular, nonspinning binaries, we uncover a puzzling result: When the binary's instantaneous 𝑀 and 𝐽 are mapped to those of a hypothetical Kerr black hole, the corresponding entropy exhibits a maximum during the evolution.

This maximum occurs at values of 𝑀 and 𝐽, strikingly close to those of the final remnant predicted by numerical relativity. Consistent behavior is observed when using the relation between 𝑀 and 𝐽 obtained from numerical relativity evolution.

Although this procedure is somewhat ad hoc, the agreement between the masses and spins of the final state obtained from numerical relativity and the results of this maximum entropy procedure is remarkable, with agreement to within a few percent when using either post-Newtonian or numerical relativity results for 𝑀 and 𝐽. These findings allow us to propose an entropy maximization conjecture for binary black hole mergers, hinting that thermodynamic principles may govern the selection of the final black hole state.

A bit dry, but intriguing. Perhaps at least a hint of a breakthrough.  On to the second item:

"Gravitational waves reveal hidden populations within black hole mergers" | Phys.org

Every time two black holes spiral together and merge, the resulting ripples in spacetime encode information about their masses and spins—the rate and direction at which each one rotates.

Astronomers can extract these properties from the gravitational-wave signal, but the picture is often incomplete: While some binaries formed from pairs of stars that lived and died together, others came together later, pulled into orbit by chance encounters in crowded stellar environments. Because these two pathways leave subtly different imprints on mass and spin, sifting through hundreds of detections to spot broader patterns has been a persistent challenge.

The first team's study, led by Cailin Plunkett at MIT, built a model that focuses on two well-measured spin parameters, capturing how a black hole's spin aligns with its orbital motion. The second study, led by Sharan Banagiri at Monash University in Australia, took a more open-ended approach, letting the data itself dictate how many distinct groups were present without assuming a particular formation story in advance.

Despite their different starting points, both teams identified a population of unusually massive black holes that stood apart from the rest, each roughly 40 times the mass of the sun or heavier.

Plunkett's team found that these heavyweights carry fast, randomly oriented spins consistent with black holes built from earlier mergers rather than stellar collapse. Banagiri's team reached a similar mass threshold and also found high spins in this group—though without the same clear signature of a merger origin. This prompted some caution about the interpretation.

Together, these findings offer some of the strongest evidence to date that a portion of observed black hole mergers are "second-generation" events, born from black holes that had already merged once before—rather than from the collapse of massive stars.

This distinction could ultimately help explain how black holes end up in a mass range otherwise thought to be off-limits, and how the seeds of the supermassive black holes at galaxies' centers might have grown. As gravitational-wave detectors grow more sensitive to these massive binaries, the boundaries between subpopulations could soon become clearer.

[Link to full article.]

Both the first and the second paper mentioned are behind paywalls. The abstracts include a fair bit of LaTex notation and arcane jargon; the links are there if anybody wants to check them out.

#45

Sports / Re: World Cup - 2026

Last post by zorkan - July 11, 2026, 01:19:47 PM

Trump and England striker Harry Kane appear to be a mutual admiration society.

https://www.bbc.co.uk/sport/football/articles/c8e2z97rp4xo

England play today against Norway in the quarter finals.
Unlike previous tournaments I've seen little enthusiasm for England.
Used to see flags on buildings and cars, outdoor screens, people talking.
Now, nearly all gone.
Maybe folk have realised that supporting them is just a triumph of hope over experience.

#46

Religion / Re: Pope Leo and Friends

Last post by zorkan - July 11, 2026, 12:31:08 PM

Send this to Leo, latest post from Janna Levin.

We have spent centuries demystifying the heavens, deposing the deities, replacing omens with calculations. The gods were myths we invited to inhabit the sky. They were evicted by Kepler's laws and Newton's calculus. In their abandoned territory, we're intending to install a geocentric swarm of space data centers with massive compute, a pantheon of machine intelligences, actual reigning overlords. As though we couldn't tolerate the spiritual void. Depose the gods; all hail the machines.

https://www.instagram.com/p/DafmZ7PDhNn/

#47

Science / Re: A Big Dinosaur

Last post by Recusant - July 10, 2026, 07:27:28 AM

Astute observation. 

Apparently there are differing opinions regarding the neck posture of sauropods. Some argue for a more horizontal posture, while others argue for an upright posture. There are a number of pages about it, and what I took from my explorations is that some of the big sauropods may have had an upright neck posture and likely many did not.

The two pages linked are only examples (it's a rabbit hole one can spend some time on) but there's a Wikipedia page on the topic that I think does a fair job of giving an overview.

I sort of assume that the artist consulted with the authors of the paper when he was creating his "artist's impression." If so it would seem they're firmly in the upright neck posture camp for this particular sauropod.

#48

Science / Re: A Big Dinosaur

Last post by Dark Lightning - July 09, 2026, 07:10:42 PM

It's amazing that the thing can even hold its head up with that long skinny neck.

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#49

Science / Re: A Big Dinosaur

Last post by Recusant - July 09, 2026, 05:28:42 PM

A newly discovered giant sauropod from Thailand. 

"A Whole New Species of Giant Dinosaur Has Just Been Identified" | ScienceAlert

An artist's impression of Uragasaurus kalasinensis. (Pakorn Chotchaiyaporn for Nilpanapan et al., Sci. Rep., 2026)

[F]rom a single vertebra found in a fossil bed in Thailand, researchers have identified a whole new species of giant dinosaur.

Its name is Uragasaurus kalasinensis, and it was a long-necked sauropod – the group of giant plant-eating dinosaurs, including Diplodocus and Brontosaurus – that lived in forests in Southeast Asia just before the Jurassic-Cretaceous transition, which began around 143 million years ago.

It's also the first formally named member of the long-necked dinosaur family Mamenchisauridae from northeastern Thailand.

"This discovery expands the known diversity of mamenchisaurid sauropods in Southeast Asia and provides new information on the geographic distribution and evolutionary history of the clade," writes a team led by paleontologist Apirut Nilpanapan of Mahasarakham University in Thailand.

[Continues . . .]

The paper is open access:

"A new mamenchisaurid sauropod from the Lower Phu Kradung Formation, Upper Jurassic of northeastern Thailand" | Scientific Reports

Abstract:

Mamenchisauridae is a group of long-necked non-neosauropodan eusauropod dinosaurs that were abundant in East Asia during the Middle to Late Jurassic, but their diversity and geographic distribution outside China remain poorly documented.

Here we describe Uragasaurus kalasinensis gen. et sp. nov., a new sauropod dinosaur from the Phu Kradung Formation of northeastern Thailand. The new taxon is based on a well-preserved anterior dorsal vertebra exhibiting a distinctive combination of characters, including a unique Y-shaped configuration formed by the intraprezygapophyseal and single intraprezygapophyseal laminae and a camellate internal pneumatic structure within the centrum revealed by computed tomography (CT).

Phylogenetic analyses recover the new taxon as an early-diverging member of Mamenchisauridae. This discovery represents the first formally named mamenchisaurid from Thailand and expands the known geographic distribution of the clade in Southeast Asia. The occurrence of this taxon in the Lower part of the Phu Kradung Formation also contributes to understanding faunal succession within the unit, supports an Upper Jurassic age for the lower part of the formation, and improves understanding of sauropod diversity in Southeast Asia during the Jurassic-Cretaceous transition.

#50

Politics / Re: Keir Starmer

Last post by zorkan - July 09, 2026, 12:37:05 PM

With Farage having resigned to fight again in his own constituency, he will have to beat Count Binface.

https://www.theguardian.com/politics/2026/jul/08/clacton-byelection-likely-to-be-two-man-race-between-reform-leader-and-binface

Quite probably the first political contest ever between a man and an alien is likely to take place in August.