Keanu Reeves, star of The Matrix and John Wick franchises, is set to appear in the second season of Netflix’s Ancient Apocalypse. In a trailer released September 18, Reeves appears alongside Graham Hancock, the show’s creator and protagonist narrator.

Hancock, a British journalist and author, is a veteran of controversy. His first season of Ancient Apocalypse received harsh criticism from the world of science. And before that, his books and attitude toward archaeology regularly provoked pushback from scientists.

After the first installment of Ancient Apocalypse, the Society for American Archaeology (SAA) wrote an open letter denouncing the series for its poor reasoning, vitriol directed at archaeologists, and acceptance of long-discredited and sometimes racist ideas. The SAA recommended Netflix reclassify the series as “science fiction” and “balance the show with scientifically accurate information about our human past.”

Stuart Heritage, a journalist writing for the Guardian in 2022, described the series thusly:

Hancock travels to Malta, to Mexico, to Indonesia, and to the US, purely so he can look at remnants of old structures and insist that they prove his theory. Which isn’t to say that is all he does, of course, because a great deal of every episode is spent railing at the buttoned-up archeological institutions that fail to listen to him (because, according to them, the whole theory doesn’t stand up to any scrutiny whatsoever).

So what does Hancock believe? Heritage again provides a nice summary:

Hancock believes that an advanced ice-age civilisation — responsible for teaching humanity concepts such as maths, architecture and agriculture — was wiped out in a giant flood brought about by multiple comet strikes about 12,000 years ago.

According to Hancock, it wasn’t the innovations and ingenuity of native populations, from Mesoamerica to Indonesia, that spurred the development of pyramids, temples, and other monumental architecture — it was a mythic Atlantean society for which there is conspicuously no direct evidence. (To explain this curiosity, Hancock claims his society was expunged from the historical record by the comet deluge and resulting flood. How convenient!)

Contrary to his earlier writings, Hancock’s newer work avoids references to the whiteness and Atlantean nature of his hypothesized society. Likely realizing these two elements are no longer fashionable and tie his ideas to historic racists like Ignatius Donnelly, a pioneer of the Atlantis myth, he quietly reshaped his exposition to modern sentiments.

Hancock’s show has an easily discernible appeal to a layperson audience with little knowledge of archaeology (or for an audience whose knowledge of archaeology comes solely from people like Hancock.) His shows are lavishly produced and visit legitimately interesting places.

Hancock’s upcoming series will focus on the Americas as the potential birthplace of this mythic civilization. These archaeological sites, according to Hancock, are “often overlooked by historians of humanity’s origins.”

According to John Hoopes, an archaeologist who specializes in prehistoric Latin America (and who refused to debate Hancock on grounds that it would legitimize his views), the trailer features several well-known archaeological locations in the Americas, including sites from Mexico, Bolivia, Brazil, Peru, and New Mexico. We see shots of the famous Palenque in Chiapas, Mexico, and witness Hancock stand awkwardly beneath a stone doorway in Sacsayhuaman, the former seat of the Incan Empire in Cusco, Peru. (I think I have posed awkwardly beneath the same doorway.)

Hoopes also anticipates a few sites not shown in the trailer that will likely get covered in the upcoming show, including the so-called “lost cities” of Upana Valley in Ecuador and cave art from a location in Serrania de la Lindosa in Colombia.

While these sites have not been studied with Hancockian assumptions, they certainly have been studied. Many of these locations see their research published in the most prestigious science journals. The reason they are never framed in Hancock’s perspective is because there is no reason to suggest the sites came from — or are in anyway related to — an elusive super-race.

It isn’t just scientists who dislike Hancock. Back in June, Hancock and his team abandoned a filming location in the Grand Canyon after public outcry from local communities. Native American groups like the Hopi protested Hancock and his team filming at their sites and tried to deny them access to filming permits. (A similar thing happened during season 1.)

It’s unclear Reeves’s role in the show. Deadline reports that he “will join Hancock throughout the series, discussing, among other things, his insights into storytelling as an act of preserving culture.” I’m unsure what insights Reeves’s will offer here, since he’s not a scholar of oral traditions, an enthographer or a linguist. I suppose we’ll have to wait and see.

Whatever his role, Reeves is doing his part to put a celebrity affiliation behind the views of a man who admitted on the Joe Rogan Experience, in a debate with archaeologist Flint Dibble, to having “no evidence” for his hypothesis (see around 1:27:00). Moreover, his endorsement is likely to push susceptible people further from the world of actual science into one of myth making and conspiratorial thinking — something I think we can agree the world has enough of.

Terror birds were wretched creatures. They grew up to nine feet tall. They crushed prey with their horse-sized skulls. They stalked ecosystems and created misery for almost everything.

A new discovery by Carolina Acosta Hospitaleche and Washington Jones, published in the journal Palaeontologia Electronica, suggests terror birds might have once ruled Antarctica.

Antarctica today is an inhospitable place. To quote the US Antarctica Program, “it is the coldest, windiest, [and] harshest continent.” Over 98% of its land is covered by thick ice sheets. Temperatures near the South Pole average -28°C (-18°F) in summer and -60°C (-76°F) in winter. Not an ideal location for your next vacation home.

Hospitaleche and Jones did their digging on Seymour Island, a small island off the northernmost tip of the Antarctic Peninsula. As they note:

This island, characterized by a fossil rich uppermost sequence, remains devoid of ice cover during the austral summer [summer in the southern hemisphere], enabling the extensive exposure of Cretaceous-Paleogene outcrops.

Cretaceous-Paleogene outcrops are 146 to 23 million years old. Hospitaleche and Jones dug in the La Meseta Formation, which dates to the Eocene (56 to 34 million years ago).

Eocene Antarctica was vastly different than Antarctica today. The land and surrounding water was warm. Fossil evidence indicates temperate rainforests like those in Chile and New Zealand. Ice core samples show temperatures around 14°C (57.2°F). Toward the end of the Eocene, things got colder.

This from another paper:

The change from a warm, ice-free greenhouse world to the glacial Antarctic icehouse occurred during the latest Eocene. … Prior to this, during the Early-Middle Eocene, Antarctica experienced warm climates... Overall, evidence from fossils, sediments and geochemistry … indicates generally warm and ice-free conditions during the earliest part of the Eocene … followed by gradual cooling.

Fossil evidence from Eocene Antarctic rock reveals abundant bird, mammal, and marsupial species. Paleontologists find ancestral penguin, duck, turtle, and starfish species. Mammals and marsupials were mostly small and herbivorous.

This from Hospitaleche and Jones:

Herbivorous groups dominated the community of land mammals and were represented by ungulates [hoofed mammals] of various sizes with dental adaptations for feeding on different types of plants. … The diversity of marsupials included small species with diverse dietary habits, including insectivores, frugivores, and folivores.

Conspicuously, Hospitaleche and Jones note, “the representation of top predators in Eocene Antarctica remains relatively under-represented.” Who were the predators?

After the Eocene, Antarctica broke from Australia and South America. The Antarctic Circumpolar Current formed, which reduced temperatures around the continent. Glaciation ebbed and flowed, but eventually formed large ice sheets. Ice sheets now cover land that would otherwise reveal details about Antarctic predators.

To see what predators might have dominated Antarctica, paleontologists look to Southern South America. South America and Antarctica were previously connected by the Paleogene Weddellian Isthmus, so Southern South America offers clues about which predators paleontologists might find.

Predator niches in South America were occupied by crocodiles, massive snakes, mid-size marsupials, and — drum roll please —Phorusrhacidae, also known as terror birds.

Terror bird remains are found throughout South America and parts of North America. Species have been identified in Argentina, Brazil, and most recently Uruguay. The largest of them, weighing over 300 kg (661 lbs), is Titanis walleri, which is from Texas and Florida in the United States.

This from the authors:

[Terror] birds are amongst the largest birds that have ever existed on the planet, ranging in height from approximately 1 to 3 meters. … They most likely preyed on small- and medium-sized vertebrates. These birds would be active hunters that fulfilled the role of continental apex predator…

Terror birds used their formidable legs, large skulls, hooked beaks, and razor-sharp ungual phalanxes to kill prey. The ungual phalanx is a distinctive, claw-like appendage used by many birds to ensnare their victims. The authors elaborate:

Hypercarnivorous birds, like Phorusrhacos, typically develop a strongly curved ungual phalanx in the second digit to capture prey during hunting.

Hospitaleche and Jones found two ungual phalanxes in the La Meseta Formation. They compared the claws with similarly aged bird species, including each of the terror birds. Their results show the claws belonged to a species that closely resembles Phorusrhacos longissimus, a terror bird from South America.

P. longissimus weighed between 117 to 134 kg, suggesting the Antarctic specimen weighed at least 100 kg (220 lbs).

More from the authors:

It is highly likely that this bird was an active predator, hunting and feeding on small marsupials and medium-sized ungulates. This finding fundamentally changes our understanding of the dynamic within the Antarctic continental ecosystems during the early Eocene. … Birds similar in size … would have been capable of preying on similarly sized prey, approximately up to 100 kg.

Modern Homo sapiens, it should be noted, weigh 60 to 80 kg on average. If there was any overlap between us and them (and fortunately there was not), we might have been on the menu.

Several Antarctic discoveries over the past decade were initially mistaken for terror birds, but later reclassified as other taxa. Hospitaleche and Jones found the first “unequivocal” evidence of terror bird species in Antarctica.

Terror birds are thought to have gone extinct in part from the Great American Biota Interchange, a process that unfolded after a land bridge formed between Panama and Colombia. While the land enabled terror birds to migrate into North America, it also allowed panthers, Smilodon (i.e., saber-toothed tigers), and a formidable short-faced bear species to venture south. These predators might have stolen terror bird territory.

Future research will invariably reveal further details about Antarctic ecosystems and their apex predators. For now, we know terror birds ruled as they once did in parts of North and South America. We should pity the animals they terrorized.

Satellite megaconstellations aim to provide 6G internet and other services to the world. While they might succeed, they might also destroy Earth.

A recent study by S. Solter-Hunt at the University of Iceland, published in the journal ArXiv, suggests megaconstellations might impact Earth’s magnetosphere. The magnetosphere protects Earth and its inhabitants from harmful cosmic radiation, so the news is concerning.

Estimates indicate that over the next few decades, hundreds of thousands of satellites will enter Low Earth Orbit in different megaconstellations (large groups of satellites with a shared goal). SpaceX is a pioneer in this pursuit. Solter-Hunt highlights SpaceX’s latest Starlink program:

The Starlink V2 satellite constellation (just one of many planned megaconstellations) intends to have 42,000 satellites, each the mass of a SUV, truck, or large car (1250+ kg).

OneWeb, Amazon, Telesat, and GW have similar programs. OneWeb plans to launch 6,000 satellites over the next few years.

Megaconstellations are no stranger to controversy. Astronomers find them particularly irritating. This from another paper:

astronomers pushed for reductions in the number and brightness of Starlink satellites after an image from a telescope in Chile was ruined. SpaceX responded by adding visors to the satellites, which has reduced their naked-eye visibility while still leaving them bright to telescopes.

The paper continues:

even a satellite that is unilluminated … can interfere with rapid time domain astronomy when it passes in front of a star. Radio astronomy is also threatened, since mega-constellations … require frequencies [like] those traditionally used by land stations.

Satellites create other problems when they die and reenter Earth’s atmosphere.

Megaconstellations are not built for longevity. They are mass-produced, disposable, and possess few backup systems. Starlink expects its satellites to last five to six years under ideal conditions, but many will fail earlier.

Once a satellite expires, it reenters Earth’s atmosphere for disposal. Travel back into Earth’s atmosphere is no picnic. Satellites careen toward Earth at speeds near orbital velocity, which — depending on altitude — is around 28,000 km/h (17,000 mph). It is a “violent” process that heats descending materials over 900°K (1163°F).

Reentry strips and melts aluminum, copper, lithium, and other material from spacecraft and leaves their remains in Earth’s upper atmosphere. Over 90% of satellite materials ablate in this way.

Solter-Hunt adds:

Since the beginning of the space industry, approximately 20,000 tons of material have been demolished during reentry, meaning a similar amount may still remain [in the upper atmosphere] as plasma dust.

Megaconstellations will greatly exacerbate this accumulation. Starlink anticipates 23 satellite reentries per day, which Solter-Hunt calculates is 29 tons of debris every 24 hours. She adds that since “this material is replenished every day, any potential natural decay to the ground may be negligible.”

Reentry debris has many known outcomes. Aluminum, for example, a metal commonly used in spacecraft to reduce weight, turns into alumina once dissolved in the atmosphere. Alumina can damage the ozone layer.

Space debris also precipitated a global winter that helped kill the dinosaurs. The Chicxulub asteroid shot mountains of soot and debris into the atmosphere when it struck Mexico’s Yucatan Peninsula. As Solter-Hunt notes:

research regarding the Chicxulub impact indicates that the dust from the asteroid was a key mechanism in the extinction of dinosaurs and life in this period. The space industry is replicating this type of asteroid dust with more extreme chemicals [and other elements] that have not had sufficient study at this time.

She adds that at 1250 kg per satellite, you only need “100,000 to 150,000 satellite re-entry demolishments … to meet the approximate mass of the Chicxulub impact.” Starlink would create this much debris after 12 years of consistent reentries.

As if that was not enough, metals in satellite dust are also conductive and increase ionization where found. Ionization is toxic to astronauts and electronic equipment. Solter-Hunt points to the South Atlantic Anomaly as an example:

The South Atlantic Anomoly … is a region of the [magnetosphere] that comes closest to the Earth at 200 km and is avoided by satellites due to an increase in ionizing radiation.

Megaconstellations, she continues, create a more global and “dangerous ionizing radiation zone with their reentry plasma dust.” Increased ionization imperils future astronauts and spacecraft, potentially making it unsafe to venture beyond Earth’s atmosphere.

Solter-Hunts fears conductive particles also deplete the magnetosphere. While the magnetosphere has already weakened 10 to 15% since first studied (for reasons not entirely understood), satellite debris might accelerate this decline.

Recent research suggests Mars might have lost its magnetosphere in part from conductive materials deposited by meteors.

Solter-Hunt clarifies:

Mars, nearer to the asteroid belt, may have endured more meteor ablation involving aluminium and other metals [than Earth]. This may have played a part in [its] magnetosphere erosion.

Satellites produce significantly more conductive debris than meteors. If conductive metals like aluminum eroded the Martian magnetosphere, satellites will do the same to Earth several times over.

Solter-Hunt explains how conductive debris can deplete a magnetosphere. If conductive material surrounds a magnetic field, the field weakens:

In a basic physics consideration, a spherical magnet (analog Earth) surrounded by a conductive spherical mesh (analog megaconstellations) would induce a drop in magnetic field outside of the conductive spherical mesh. This would allow solar energizing particles to more easily reach the satellite regions (and atmosphere).

Solter-Hunt notes we do not ultimately know how conductive particles will affect Earth or its magnetosphere. We do know the magnetosphere shields us from lethal solar radiation, so further research is needed.

Fortunately, we are not hopeless. While legislation is sparse and procedures loosely regulated, there are signs companies might cooperate to address concerns. Hopefully we can avoid another dust cloud like the one that ended the dinosaurs.

Roman wine, and ancient wine more broadly, is enigmatic. While notable Roman figures wrote about wines, their properties, and which varieties make good laxatives, they seldom clarified how specific practices led to specific flavors. They also never hid any away for 21st century scholars to imbibe and assess.

New research by archaeologists Dimitri Van Limbergen and Paulina Komar, published in the journal Antiquity, illuminates some of the mysteries surrounding Roman wine. They might have even discovered the secret behind Rome’s finest wines.

Rome had a unique method of vinification (winemaking). Unlike modern techniques where wine is fermented above ground in steel, oak, or concrete containers, Roman wine was fermented underground in clay containers called dolia.

Dolia cellars are found throughout Italy and former parts of the Western Roman Empire. They are found in particularly great abundance in urban centers like Ravenna, Pompeii, and Rome.

Only recently have dolia been considered worth studying. Recent analyses show they were made of clays extracted from select and often distant locations. As the authors note, “these vessels were highly valued items that were made by skilled artisans using specially selected mixtures.”

While prior studies on Roman winemaking reference dolia, none connect them to specific flavors or aromas. To better understand dolia and the wines they produced, Limbergen and Komar looked to Georgia.

Georgia and the surrounding Caucasus (land between the Black and Caspien Seas) are the earliest places where wine was fermented in this style. This history dates back to the early Neolithic and continues to the modern day. In Georgia, the practice is so well preserved it was classified a UNESCO World Intangible Cultural Heritage in 2013. They practiced this style of winemaking for over 8,000 years.

The earliest site in which earthenware vessels are buried is an Armenian cave, called Areni-1, which dates between 4,000 and 3,500 BCE. There are spherical ceramic vessels from Georgia dating to 5,800 BCE, suggesting the practice is even older. Researchers think these methods traveled to the Phoenicians who then took them to Italy.

Georgians called their vessels qvevri. Limbergen and Komar describe similarities between qvervi and dolia and why the Georgian vessel can help us understand Roman wines:

Dolia and qvevri are similar vessels in terms of material, shape and setting and the winemaking process for both vessels is broadly the same. Qvevri vinification procedures are, however, documented in much more detail. A comparative study therefore has the potential to greatly enhance our interpretation of the ancient textual sources on viticulture and winemaking.

In addition to vessel structure, Rome and Georgia have similar climates and used grapes with high genetic relatedness. The similarities further illustrate why qvervi are ideal for comparison.

Qvervi are built for natural wines, which means they use yeasts that occur organically on grape skins for fermentation. Roman dolia are the same. The main wine yeast is Saccharomyces cerevisiae.

S. cerevisiae is the wine-fermenting king. Not only does it eat grape juice sugars and turn them into alcohol (the name Saccharomyces alludes to the saccharide sugars it eats), it also produces enough alcohol to kill competing microorganisms, leaving more sugar for itself.

Yeasts like S. cerevisiae convert most sugars to alcohol early in the winemaking process. This stage is called primary fermentation. In Rome, primary fermentation lasted nine to 30 days.

Dolia were kept open during primary fermentation, which allowed carbon dioxide emitted from S. cerevisiae to escape the vessel. (If you bottle dolia too quickly, they can crack from trapped carbon dioxide.) The mixture was then capped with a wooden lid, animal skin, or terracotta disk (called an operculum). Once bottled, dolia were kept beneath ground for five to six months.

The Georgian practice is similar. This from the authors:

primary fermentation in qvevri lasts two to three weeks, during which the jars remain open… After two to three weeks, the vessels are sealed with a stone or wooden lid and covered with earth, remaining so for six to nine months.

Fine wines were transferred to new vessels and aged for much longer (typically five to 25 years). To sustain healthy aging, fine wines needed grapes with extra sugar.

More sugar means stronger wines: The more sugar in grapes, the more alcohol S. cerevisiae creates. Alcohol in turn prevents the formation of bacteria that degrade wine as it ages. The worst bacteria is Acetobacter, which turns alcohol into sour-tasting acetic acids (a key ingredient in vinegar). To ensure wines had enough sugar, Romans used sun-dried grapes or sun-dried grapes soaked in wine.

Rome used sugary grapes to prepare several strong, fine wines. The most acclaimed was Falernian. From another paper:

The most expensive and luxury wine of Rome was the Falernian wine (from Falernum region), … which could age well for dozens of years… Falernian would be amber in color and highly alcoholic. It was made from the Aminea white grape variety.

White grapes regularly yield amber-colored wines when made in dolia or qvervi. Limbergen and Komar note how:

Once primary fermentation inside a clay vessel is complete, the grape solids sink naturally to the bottom of the vessel, where they concentrate in its flat and narrow base. At this stage, these solids are removed for red wines, but for white wines they are left in contact with the [grape juice] for several months to extract colour [and other elements]. This results in dark yellow, amber-coloured wines… akin to what is described in ancient Roman texts.

Many of Rome’s finest wines were white, but there were of course others. According to Pliny the Elder (23 — 79 CE), Roman wine came in four colors: pale white, reddish-yellow, blood-red, and black.

Black wine likely came from a specific type of red grape. Its wine was notoriously difficult to digest and only recommended as a laxative. One paper noted this is not usually an attribute of quality wine. Galen (129 — 199 CE), the famous Greek physician, agreed. This from another paper:

It was not appropriate, as [Galan] wrote, to serve dry or sour wine, which was thick and black at the same time, during a symposium or wedding reception, as an offering to gods, or during any other occasion whatsoever.

Other wines were created through a mixture of grape type, contact with the pomace (the dregs of leftover grape skins, seeds, and stems), and various degrees of oxidation.

Dolia and qvervi are porous, which means their wines get exposed to oxygen after concealment. Significant oxidation allows Acetobacter bacteria to proliferate and turn wine into vinegar, but mild amounts create fine wines with a unique flavor. To mitigate excessive oxidation, the interior walls of dolia were coated with pitch. Qvervi were coated with beeswax.

Fine oxidative wines are usually drier and characterized by flor yeasts, primarily S. cerevisiae, that form atop the wine as it ages (called “flor” because they look like flowers). These yeasts only form when there is enough sugar for them to proliferate. When they do form, they secrete chemicals that affect a wine’s taste. The most significant of these chemicals is sotolon.

Sotolon-infused wines are spicy. To quote the authors, sotolon “imparts aromas of toasted bread, apples, roasted walnuts, and curry.” These spicy notes were important elements in fine Roman wines.

Rome underwent steps to ensure its best wines formed sotolon. Dolia were stored at optimal temperatures to develop S. cerevisiae flor yeasts and used prepared grapes with a high sugar content.

Low quality wines were often dressed up to mimic sotolon wines. Columella (4 — 70 CE), a Roman author who discussed wine at length in his De Re Rustica, wrote that cheap wine was often supplemented with fenugreek, a flower with sotolon-like tastes and smells. The addition was a post hoc attempt to emulate finer wines.

Limbergen and Komar point to research that followed Columella’s descriptions of the winemaking process to see what kind of wine they made. The wine was amber-colored and, according to volunteers who drank it, “very sweet and spicy.”

Romans employed many tactics to tweak the tastes of wine. Falernian wine, for example, came in both dry and sweet varieties. The dry version was likely untouched by additives, whereas as the sweet version might have been supplemented with honey. Whatever the variety, the final brew was likely spicy.

While the authors suggest more research needs to be done — especially on clay vessels and their contribution to taste — they have undoubtedly increased our understanding of fine Roman wines and their construction. If you want to drink like Claudius or Nero, traditional Georgian wine is your best bet. Alternatively, you could just find some fenugreek.

If you had to name one dinosaur, odds are you would pick Tyrannosaurus rex. Most people are keenly aware of the tyrant lizard king, its literal bone-crushing jaws, and the terror it reigned over Mesozoic fauna. Most people are unaware that paleontologists do not know its full history.

A new study led by paleontologist Sebastian G. Dalman, published in the journal Nature, provides fresh insight into the origins of T. rex and its closely-related kin. This research depicts a significantly more American-centered genesis than previously believed.

T. rex belongs to a group of dinosaurs called tyrannosaurids. These dinosaurs had huge skulls, banana-shaped teeth, absurdly tiny forelimbs, and finely developed senses that kept them at the top of the food chain. They also had jaws strong enough to crush bone. To quote from another paper:

Tyrannosaurids characteristically bit deeply into carcasses, often through bones… Some T. rex bite marks… indicate that bone was fractured, ingested, and used for sustenance… The bite forces needed to crunch through bone would have been enormous.

Tyrannosaurids ate bone so regularly it wore down their teeth. They also ate giants with large bones.

Early in the Cretaceous (145 to 66 million years ago), tyrannosaurids had yet to evolve. They were preceded by smaller species — called tyrannosauroids — that were seldom larger than horses. It wasn’t until the final 20 million years of the Cretaceous that they emerged as massive hypercarnivores like the T. rex.

T. rex’s size in particular was incredible. It could grow up to 42 feet long (13 m) and weigh 20,000 lbs (10 tons). The Toyota Rav4 is 15 feet long and 3,500 lbs. You would need six Rav4s stacked two cars high and three cars wide to match the size and weight of T. rex.

As Dalman notes, T. rex was “the last and largest tyrannosaurid.” It was possibly the largest apex land predator to ever exist. Unfortunately, it appeared just 1 to 2 million years before the asteroid that ended the Age of Dinosaurs. It had a short run.

Until recently, tyrannosaurid evolution has been somewhat mysterious. There is a 20-million-year gap in the fossil record where the transition from small precursor species (with normal forelimbs) to large megapredators takes place. Because of these missing fossils, paleontologists struggle to understand tyrannosaurid geography: T. rex is found exclusively in the southwestern United States, while its most closely-related sister species are found in Mongolia.

Fossil evidence to this point indicated an Asian origin for tyrannosaurids. Tarbosaurus bataar, a tyrannosaurid from Mongolia (and a species actor Nicolas Cage once bought at auction), and Zhuchengtyrannus magnus, an even older tyrannosaurid from China, predate the evolution of T. rex by millions of years. This age difference suggests the tyrannosaurid ancestor spread through Asia before heading east into North America.

Another paper phrased it thusly, clarifying that T. rex would later evolve from this migrant ancestor:

The abundance of definite, large [tyrannosaurid and other closely-related fossils from Asia], which are older than Tyrannosaurus rex, favors the hypothesis of Tyrannosaurus rex as the descendant of immigrant species from Asia.

Darlan’s findings challenge this hypothesis. His team unearthed remains of a new tyrannosaurid, Tyrannosaurus mcraeensis, from the Hall Lake Formation in New Mexico. These remains are older than T. rex and shift the hypothesis toward a North American genesis.

T. macraeensis, affectionately named “NMMNH P-3698,” was part of an ecosystem of large dinosaurs local to the southwestern United States (in places like Utah, Texas, and New Mexico). This group included other giants like Sierraceratops, Hadrosaurid, and the amusingly named Alamosaurus. The North American tyrannosaurids likely evolved their massive size to prey on these gigantic megafauna.

Initially, T. macraeensis was mistaken for another T. rex. It is comparably large and shares many anatomical features. Darlan clarifies how his team changed their classification:

the characters that diagnose T. mcraeensis and differentiate it from T. rex are relatively subtle characters relating to the shape and articulation of the skull bones, but because T. rex is known from multiple individuals, it is possible to show that T. mcraeensis lies outside of the range of individual variation seen in T. rex.

Darlan continues, stating that

NMMNH P-3698 is unlike any other specimen referred to T. rex… each bone has at least one diagnostic character, it is therefore an outlier from all other specimens referred to T. rex, in every element.

Radiometric dating suggests the remains, including teeth, a mandible, and parts of the skull, predate T. rex by 7 million years. Morphological and phylogenetic analyses corroborate these findings and establish that T. mcraeensis is more closely related to T. rex than any of its Asian counterparts. They also clarify that T. macraeensis is a sister species to T. rex, not a direct ancestor.

Darlan posits two distinct tyrannosaurid lineages to explain this discovery: one that “dispersed to Asia giving rise to Tarbosaurus and Zhuchengtyrannus,” and another that stayed in the southwestern United States to yield T. macraeensis and T. rex. To phrase it differently: the direct ancestor of T. rex was no migrant.

Future findings will certainly clarify these migration patterns. We live in the Golden Age of tyrannosaur research, where new discoveries are frequent. It is possible future research might point us in another direction. For now, the United States can celebrate the T. rex-sized privilege.