What did Spinosaurus Look Like Part 2: Short Arms?

Originally, I came to the conclusion that Spinosaurus would've been a quadruped. This was due to the fact that Spinosaurus had long arms but short claws that were not robust, trace fossils of theropod arm and hand marks, and I kept getting a large center of mass for the animal. However, I noticed a pattern regarding a spinosauroid manual ungual from Ibrahim et al., (2020a) and the reconstructed Spinosaurus arm from DinoLab a few years back. It led me to a new possibility: Spinosaurus probably had short arms! If Spinosaurus was bipedal, then this is probably the best hypothesis to make it so.

I've learned over time to let go of my biases in order to get to the truth of a particular matter. It's been a gradual process with Spinosaurus, but it's better late than never. Let's suppose that Spinosaurus wasn't a quadruped. Let's agree that Spinosaurus' arms weren't capable of supporting its weight. Suppose that it's center of mass was shorter than its femoral length, allowing it to be a biped. These conclusions came from Sereno et al., (2022). However, we're also going to add Ibrahim et al., (2020a) and the reconstructed arm from DinoLab into the equation. Sereno et al., (2022) showed that about 90% of the arm for the reconstructed skeleton is a composite (then again, the whole skeleton is a composite). Only one phalange, and one manual ungual, came from the neotype. The phalange belongs on the second finger (Sereno et al., 2022) (Fabbri et al., 2022). The manual ungual is on the third digit, and it is very small (Fabbri et al., 2022). The phalange is elongated and skinny (Sereno et al., 2022) (Fabbri et al., 2022), just like the phalanges on the reconstructed arm from DinoLab. So far, so good! I also noted that, in my original post announcement about the DinoLab arm, I stated that the arm looked smaller than the arms on the reconstructed skeleton made by Ibrahim, Sereno, and co. It should be noted that the metacarpals (not shown), phalanges, and the radius and ulna (they are partially complete), are real material. The humerus is a "cast"/"articulated." There is also some criticism towards the third finger being way too long, but it's not conclusive. This comes from DinoLab on their Facebook post, and Paleontologist Roberto Diaz Sibaja from Facebook as well. Terry from DinoLab said that some paleontologists have verified the bones (that are real) to be conclusive (Facebook), so we seem to be on the right path here. I will also ignore the radius from Goo (2022) for now. 

DinoLab Spinosaurus arm (Facebook, 2021):

Compare the claws to the spinosauroid claw (NMC 41820) from Ibrahim et al., (2020a) (Figure 111A-B):

Full figure. Scale bar is 5 cm:

Description of NMC 41820 (Ibrahim et al., 2020a, Theropoda: Manual ungual morphotype 1):

Information on Spinosaurus arm from DinoLab (Facebook, 2021):

Another pic of the DinoLab arm (The Zone @91-3, 2021):

Pics of DinoLab arm from Twitter-X (2020):
First:

Second (Notice that the arm looks smaller here):

Spinosaurus' skeletal design by Sereno et al., (2022) (Figure 1). The neotype's bones are blue. The phalange in D is not from the neotype though. It's from the first digit, not the second. Scale bar for D is 3 cm:

Spinosaurus skeleton from Fabbri et al., (2022) (Figure 1). The red bones are from the neotype:

Close up of the hand. You can see phalange 2-1, and manual ungual 3, in red:

So in total, we have a Spinosaurus arm that consists of a (probable) small and stocky radius and ulna, slender manual phalanges, and small manual unguals that were not recurved as typically seen in the other spinosauroids like the baryonychinae. The humerus is unknown, but we can speculate that it was probably smaller than the one from DinoLab and shaped more akin to a baryonychinae. Taking all of this into account, one could speculate that Spinosaurus' arms were probably shorter than typically reconstructed. I would imagine that Spinosaurus could've taken the tyrannosaurid and carcharodontosaurid route: Evolve larger skulls that replaced the necessity to have long arms. In return, the forelimbs would be reduced in size. 

This is, by no means, the final say in the matter. There is something strange with the arms of Spinosaurus, which leads me to believe that they were probably not very useful to the animal in life. There are other factors that still go against a strictly bipedal Spinosaurus (see part 1 of this series). Until more bones are discovered (hopefully from the neotype specimen), I'll say that Spinosaurus could've been quadrupedal IF it had long arms. I can't see Spinosaurus dragging is arms across the ground while being bipedal. If it had short arms, then I will say that Spinosaurus was bipedal. 

Links:
Part 1:
https://psdinosaurs.blogspot.com/2023/03/what-did-spinosaurus-look-like-part-1.html
Ibrahim et al., (2020a):
https://zookeys.pensoft.net/article/47517/element/7/0/deltadromeus/
DinoLab:
1.) Instagram (Gramho):
https://gramho.com/media/2535465340537444071
2.) Facebook:
https://m.facebook.com/dinolabinc/posts/our-spinosaurus-arm-is-still-on-display-we-arent-sure-how-much-longer-we-are-goi/885524165571071/
3.) Twitter-X:
https://mobile.twitter.com/DinoLab_Inc/status/1322305140020269058
4.) The Zone @91-3:
-Photo:
https://images.app.goo.gl/FYeo7rjhQr6cPLja7
-Website:
https://www.thezone.fm/2020/09/02/geekout-dino-lab-spino-arm/
Sereno et al., (2022):
https://www.biorxiv.org/content/10.1101/2022.05.25.493395v1.full
Fabbri et al., (2022):
https://www.nature.com/articles/s41586-022-04528-0.epdf?sharing_token=rxUUwyZxDWQ24dJfwtIw89RgN0jAjWel9jnR3ZoTv0NEFj8DFZa3bazFWKdXldNTvT8T3daJQzYMUbPXaqso6c2KKBgthBeOpsV72_JOZHeSlOxZzzE9wUggHYItKT5ASyn5r0hTiRPfCQi_Cfe9RPf0tvCNFd3T4QXE2UU4r7wR-SYYL4_TSvBiBpniofeQoStgnv6yWzzkL81Gcy2g6hKT9nO8ozsufeY9DwX1VK-Vsw94pFBHTtBWnm2-q0bJ33Xx2cPSUh5t7T-nx3NDvtkT9MSkWBYPTw7aqWM5FRs%3D&tracking_referrer=www.sciencenews.org
Mr. Sibaja (Palaeos):
1.) Facebook Post:
https://m.facebook.com/PalaeosPag/photos/a.157631294723661/1059058504580931
2.) Blog:
https://palaeos-blog.blogspot.com/?m=0

(Rant) Hollywood Needs to STOP!

Jurassic World Rebirth poster:

I've been thinking about this all night last night. The catalyst for this rant is that, yesterday, I heard that Shrek 5 is coming out. There's a controversy about the design of Shrek for the upcoming film, but that's not my main concern. I'm more upset that another Shrek film is coming out. The last one came out in 2010. That was about 15 years ago! The franchise was over. But no, Hollywood needs more of our hard-earned money so they're going back to milk the Shrek franchise some more. The problem isn't just with Shrek though. Hollywood is deliberately ruining every franchise that it has in the pursuit of money. How to Train Your Dragon is getting rebooted in live-action. Kung Fu Panda 4 came out last year, and it wasn't well-received by the fans. The Marvel Cinematic Universe (MCU) lost its way in every way possible. The last MCU film I saw was Spider-Man: No Way Home. I have no idea what the story is now in that universe, nor do I really care now. Disney is remaking every one of its classic animated films in live-action, and they're getting worse every time. Disney also own the MCU, so no wonder that universe is so screwed up. Disney also ruined Indiana Jones, and Star Wars. Walking With Dinosaurs is getting remade. Heck, there was a rumor earlier this week about the entire Walking With Trilogy getting remade! Finally, Jurassic World is getting rebooted with Jurassic World Rebirth coming out this year...

Are you serious, Hollywood? Are you so desperate for cash that you cannot create a single new property? You have to bring back classic stuff, ruin it, and then expect us to watch it? What do I mean by "ruin?" Well, I've noticed that every time a new film or television show in a franchise comes out, it ruins the franchise with its terrible writing, and having modern-day politics stuffed into them. Most of the politics shoved into these films and shows are Left-Wing politics. However, there are Right-Wing TV shows and whatnot out there as well. I don't want ANY of this stuff in my entertainment. I want to forget about real-world problems, and escape into a fantasy world for about an hour or so. If you want to put in lessons, then focus on universal lessons like the entertainment of the past used to do: treat others the way you want them to treat you, help each other in our times of need, learning to be friends despite our differences, etc. Nowadays, everything is about us vs. them, or me vs. you. One sex, gender, ethnicity, or group of people in general, is better than the other. You're a villain if you say this, or think that. The list goes on. There's no universal lesson to help inspire people for the better. It's about inspiring division, and hatred. Characters in a franchise are changed in order to make them fit with the current political, or idealogical, climate. Instead of making them better, this ruins them from what they used to be before. One great example is Luke Skywalker from Star Wars. Disney ruined his character in their films (I refuse to call Disney's Star Wars films the Sequel Trilogy) in order to make Rey, and even Leia, better then him. Other male characters were made to look worse in those films compared to their female counterparts as well. There's no equality there. Aren't men and women suppose to work together, and love each other? The movies and shows of the past taught me that lesson. Heck, the franchise can be totally rebranded into something different but still carry the name of the franchise. This is just nostalgia bait designed to suck in fans of the franchise and take their money. For example, Walking With Dinosaurs (2025) will have a completely different setup from the original show. Second, it's going to feature two episodes with Pachyrhinosaurus. We saw that before in the Walking With Dinosaurs film back in 2013! Why is everybody shoving Pachyrhinosaurus into their dinosaur documentaries and films!? I'm not hating on the animal. I'm questioning the decisions of the filmmakers. This show will be Walking With Dinosaurs in name only, just like the film was. The stories in these films and shows aren't interesting, and they are repeated over and over again.

Speaking of stories, let's talk about Jurassic World Rebirth. The trailer stated that there's some kind of disease, virus, etc., roaming around and a cure needs to be made. It requires dinosaur DNA in order to be made. A team heads to the island where the first dinosaurs for Jurassic Park were made (Isla Sorna), and then get put into a wild adventure. Spinosaurus returns (not the original one from JP3), and there's even a new dinosaur hybrid in the film! Does this film sound familiar to you? It does because we've seen this film FIVE TIMES BEFORE!!! Enough of the hybrids! Why didn't you bring back the JP3 Spinosaurus? Why do we need to go back to Sorna AGAIN!? Stop ruining my favorite island in the franchise! In fact, enough with the islands period! The Jurassic franchise NEEDS to end. I'm so tired of watching one of my favorite franchises get destroyed. As far as I'm concerned, only Jurassic Park (1993) and The Lost World Jurassic Park (1997) are canon. End it already!

If something is new, it's filled with modern-day political garbage as well. It's a no-win situation here: Something new? It's a political message getting shoved down your throat. Is it a remake, sequel, prequel, or a reboot? It's political mumbo jumbo being forced upon you, and ruining the franchise. Notice how entertainment isn't the main goal of Hollywood, while it should be!

I should also mention that it's not just Hollywood ruining entertainment. Video games have fallen hard as well. Huge prices for only 50% of the whole game, always online, pay-to-win and live services, bugs and glitches, huge updates that take way too long to be added, terrible writing and characters (including the character designs), and yes, modern-day politics. Mostly, it's Left-Wing politics. Not to mention, they. expect me to pay almost $1000 dollars for a new console that doesn't work any better than the one I already have! Also yes, classic gaming franchises are being censored, rebooted horribly, or continued with sequels and prequels that ruin the story and characters. Heck, even if it's a completely new game, it's ruined by the same problems stated previously.

If you dare to say something about the state of entertainment nowadays, people will attack you as if you're crazy or are a terrible person, calling you every kind of name possible other than the one your parents gave you. As I've stated previously, the entertainment of my childhood, and even teenage years, taught me good lessons as to how to treat people. It inspired me to be a better person, especially when I had a bad day and/or wanted to give up. I had the first six Star Wars films, the original Walking With Quadrilogy (watch Walking With Cavemen!), the Indiana Jones Quadrilogy, Jurassic Park (1993) and The Lost World Jurassic Park (1997), the classic animated Disney films and shows and Disney films like Dinosaur (2000), The Land Before Time, The DC Animated Universe and DC films, animated Marvel TV shows and Marvel films, and the list goes on! Heck, for video games, I had stuff like the Sly Cooper trilogy. I was inspired so much by all of these things. Where is the creativity nowadays? Where are the lessons that helps us to become better people? 

Entertainment is gone. Well, I must clarify: big corporate entities have ruined entertainment. Individuals who have a dream, and a story to tell, are the only saviors for entertainment. I watch mainly old films and shows, and play older games, nowadays. I will not watch Jurassic World Rebirth, Walking With Dinosaurs (2025), or any modern-day continuation or reboot of my favorite franchises. If this means anything to you too, dear ready, do not give Hollywood, or anybody that ruins your favorite entertainment property, any of your money.

Update (3/4/25):
I just saw that Jurassic World Chaos Theory is being brought back due to Jurassic World Rebirth coming out. My friends on Discord said that the creators of Chaos Theory stated that season 3 was the final one for the show. They all agreed that this is nothing but "corporate greed." They're absolutely right. The Jurassic franchise is dead.

(Biography) The Determination of Louis R. Purnell Jr.

It's the end of February, a.k.a Black History Month. I wanted to take a brief moment to discuss the career of a man who, honestly, helped to reinvigorate my passion for prehistory. Long story short, late 2021-2023 were very challenging years for me and I kind of lost some of my passion for paleontology. However, in late 2023, I found strength in the story of Louis Purnell Jr. Now that I'm moving on with my life, and I regained my passion for paleontology, I wanted to write this post to discuss Mr. Purnell's career at the Smithsonian Museum of Natural History. 

Louis R. Purnell Jr. as Curator of the National Air and Space Museum (1980s) (The Smithsonian Institution Archives):

According to the Smithsonian Institution Archives, "Louis R. Purnell Jr. was born in 1920" in "Maryland's Eastern Shore," (Smithsonian Institution Archives, African American Groundbreakers at the Smithsonian: Challenges and Achievements, Louis R. Purnell: The Education of Louis R. Purnell, para. 1). After serving as a pilot, and lieutenant in the Tuskegee Airmen, in World War 2 (Into the Air), Purnell got a BS in Psychology at Lincoln University (Into the Air, para. 1; An Insatiable Curiosity, para. 2). In order to make some money for his family, he worked at the Post Office. Looking for some excitement though, he went through a number of different jobs until he landed at the Smithsonian Museum of Natural History in 1961. He became a "museum specialist in the Division of Invertebrate Paleontology and Paleobotany," (An Insatiable Curiosity, para. 1-2). He went on several expeditions to collect specimens, and studied the nautiloid collection in the Smithsonian (An Insatiable Curiosity, para. 5-6). This is where Purnell gets into trouble. He noticed that some specimens were missing, and eventually found them. He was going to "write a new catalog based on his research." However, his colleagues said that he was crazy because he didn't have an education in Geology. Purnell took some "classes at George Washington University to learn how to identify the nautiloids and cephalopods that were in the Smithsonian's collections." He published his catalogue in 1968, and the Smithsonian Institution Archives said that it's "still in use today," (para. 6). It's also stated that Purnell "taught himself Geology and paleontology," (Louis R. Purnell, para. 1). The journey to finishing his catalogue was a rough one, due to "the collections manager" trying to stop him. This was due to, once again, Purnell not having a degree in Geology. Even when his catalogue was finished, most of the credit went to his supervisors in the Forward section of the work. These supervisors were the same people who tried to thwart him from publishing his catalogue! Purnell was also promised that he would get a promotion after he published his catalogue. Unfortunately, this didn't happen. Luckily, Purnell never let this experience subdue his "intellectual ambition" (An Insatiable Curiosity, para. 7). 

Purnell had success at the National Air and Space Museum (The National Air and Space Museum), but I wanted to focus on Purnell's experience at the Natural History Museum. I've had a similar experience to Purnell back in 2022-2023. Purnell had a strong will to never give up. He said that "he learned to 'roll with the punches' and 'overlook - not forgive, but overlook - [the] prejudice' he faced," (The National Air and Space Museum, para. 8). You have to get around any barrier (para. 9). Racial barriers were very large during Purnell's time with the Smithsonian (The National Air and Space Museum, para. 1, and 8-9). Nowadays, it's gender and political barriers in the sciences in general. Paleontology has been hit by this as well, and I went through it firsthand. I don't know about racial prejudice in paleontology, but I doubt that it doesn't exist presently in the science. Racism, in general, never goes away. However, no matter who you are, you have to keep going if you want to succeed. That's something that I had to remind myself of.

I hope that Purnell's story inspires you, like it did for me. I'll also leave the link to Purnell's catalogue for you to read if you're interested.

Links: 
Smithsonian Institution Archives. African American Groundbreakers at the Smithsonian: Challenges and Achievements. Louis R. Purnell: 
https://siarchives.si.edu/history/featured-topics/African-Americans/louis-purnell
-Purnell's Nautiloid catalgoue:
https://repository.si.edu/bitstream/handle/10088/10174/USNMB_2621968_unit.pdf?sequence=1&isAllowed=y

Nanotyrannus as an Eutyrannosaurian (Abstract).

Link:
https://www.academia.edu/126691661/Nanotyrannus_as_an_Eutyrannosaurian_Abstract_

                                                                        Abstract

Throughout 2024, several publications have shed new light on the highly-debated tyrannosauroid taxon Nanotyrannus lancensis, or as this author calls it, Nanotyrannus/Dryptosaurus lancensis. Nanotyrannus has been placed outside of tyrannosauridae, and into the basal tyrannosauroidea clade. Even more surprising, the holotype of Nanotyrannus, CMNH 7541, had an external fundamental system (EFS) located within its hyoid. This indicates that the specimen was an adult. Although we now have a mature specimen for the species, this author raises a question: where does Nanotyrannus lie within tyrannosauroidea? There are two groups within the basal tyrannosauroidea clade: pantyrannosauria and eutyrannosauria. Based on the skeletal characteristics Nanotyrannus shares with Raptorex, Dryptosaurus, and Appalachiosaurus, and since the latter two taxa are within eutyrannosauria, this author hypothesizes that Nanotyrannus can be placed within eutyrannosauria. This author also believes that Raptorex, another debated tyrannosaur, could fit within eutyrannosauria as well. Another potential member is the Bissekty tyrannosauroid. A possible hypothetical growth series for Nanotyrannus could be the following: BMRP 2002.4.1 (“Jane”), BMRP 2006.4.4 (“Petey”), and CMNH 7541. 

(News) Hello Allosaurus anax, and Goodbye "Saurophaganax" (Danison et al., 2024b)!

"Saurophaganax" skeleton (Sam Noble Museum/Oklahoma Museum of Natural History Facebook Reel):

It's okay, "Saurophaganax." You can rest now (paraphrased from Avengers Endgame, 2019).

I knew some Allosaurus bones got mixed in with the "Saurophaganax" material! I've been saying this for years. Now, a new paper written by Danison et al. states exactly what I've been saying! 

Note: Download the paper. Some things in the abstract are different from what's stated in the paper.

"Saurophaganax" is officially a nomen dubium, and a chimera (pp. 81, 106, and 108). The atlas and dorsal vertebrae, and chevrons, are neosauropoda (like Camarasaurus), a diplodocid, or nomen dubium (pp. 81, 89-90, 93-95, and 108-109). Amazingly, the authors recognized that carcharodontosaurids had similar morphologies in their dorsal vertebrae compared to "Saurophaganax's" (the "Saurophaganax" holotype OMNH 1123), in particular Tyrannotitan/Giganotosaurus chubutensis and Lusovenator! I said that! However, the authors disagreed that OMNH 1123 could be definitively referred to a theropod. They didn't even know if it could accurately be assigned to a sauropod, but they decided that it probably was a sauropod that resembled Apatosaurus sp. (pp. 93 and 95). Either way, they put OMNH 1123 as a nomen dubium (pp. 95 and 108). I was right about "Saurophaganax" being a chimera! I'm also surprised that the authors also noticed a possible carcharodontosaurid connection to "Saurophaganax!" 

Atlas vertebrae of Allosaurus jimmadseni (A), "Saurophaganax" (B), and Camarasaurus sp. (C) (p. 89 Figure 4):

"Saurophaganax" holotype OMNH 1123 (A) compared to Apatosaurus sp. OMNH 1366 (B). The sprl in Apatosaurus sp. seem to match the al in "Saurophaganax" (p. 94 Figure 8):

See p. 93 for the comparison between the laminae of the two bones. I wonder... Are the laminae in OMNH 1123 so wide because the specimen was a hatchling, or juvenile? If the animal grew, would the laminae become elongated like Apatosaurus' are? That's just a guess though.

The Allosaurus material was either named Allosaurus anax, or Allosaurus sp. (pp. 82-83, 106-109). The giant humerus, OMNH 1935, which I thought had to be Allosaurus, was "indistinguishable from that of Allosaurus fragilis and Allosaurus jimmadseni." The authors said it was an allosaurid, despite it's great size (pp. 100-101, and 106), but for some reason they didn't put it as Allosaurus anax or Allosaurus sp. Since the authors agreed with me that OMNH 1935 was basically Allosaurus, I'll put the giant humerus as Allosaurus sp. myself. 

Originally, I put the femora in Allosaurus but switched to putting it in "Saurophaganax." I also put the tibiae in "Saurophaganax." It turns out that the femora were Allosaurus after all, but not A. fragilis or A. jimmadseni. The authors called it Allosaurus sp. (pp. 102 and 109). The tibiae were also assigned to Allosaurus sp. (pp. 104 and 109). The postorbital, a cervical vertebra, two dorsal centrum, and fibulae, were assigned to Allosaurus anax and not "Saurophaganax" (pp. 82-83, and 108-109). The metatarsals, which I thought were either Allosaurus or a carcharodontosaurid, were put under Allosaurus sp. (pp. 106 and 109). I was VERY conservative in estimating how much of the "Saurophaganax" material belonged to Allosaurus! That is shocking!

Speaking of Allosaurus maximus, it's a synonym of "Saurophaganax maximus" because it used the specimen OMNH 1123 as the holotype. That's probably the reason why Allosaurus anax was erected as the new genus name, along with the fact that the authors see the Allosaurus material as distinct from A. fragilis and A. jimmadseni (p. 107).

"Saurophaganax" was a chimera (like I've stated before), and a nomen dubium. "Saurophaganax" wasn't even a carcharodontosaurid, like I originally hypothesized. It probably didn't even exist! However, I'm just glad that I was right about the Allosaurus bones being lumped into the "Saurophaganax" material. Heck, almost all of the bones were Allosaurus sp. or Allosaurus anax! I wasn't going far enough! However, it's good to double-check and be cautious at times. 

Vindication, once again! Nanotyrannus is a basal tyrannosauroid, and the holotype was an adult specimen with an EFS in its hyoid bone! Now, "Saurophaganax" is a confirmed chimera and had Allosaurus bones in it!

Hello Allosaurus anax, and goodbye "Saurophaganax maximus." 

Link:
Danison et al., (2024b):
https://journals.library.ualberta.ca/vamp/index.php/VAMP/article/view/29404
"Saurophaganax" skeleton (Sam Noble Museum/Oklahoma Museum of Natural History Facebook Reel):
https://www.facebook.com/reel/1063663955214929
-Pic:
https://images.app.goo.gl/QoSobE8zMQ7QGo3g7
-Sam Noble Museum’s Facebook Page:
https://www.facebook.com/SamNobleMuseum/reels/
My previous post on "Saurophaganax" being a carcharodontosaurid:
https://psdinosaurs.blogspot.com/2019/12/is-saurophaganax-carcharodontosaurid_21.html
My abstract:
https://www.academia.edu/101770036/Saurophaganax_is_a_Carcharodontosaurid_An_Abstract

(News) Is Saurophaganax a chimera (Danison et al., 2024a)!?

Saurophaganax in Planet Dinosaur (2011):

I already talked about one abstract from SVP (2024), but there's another one that I need to discuss regarding another theropod I've talked about before.

We finally got some more research on the enigmatic theropod, Saurophaganax, brought to us by Danison et al., (2024). However, the authors of this abstract have made some pretty surprising claims that could change our view on the theropod completely... For example, the scientists claim that Saurophaganax wasn't even a theropod!

Danison et al., (2024) examined the Saurophaganax material. They started off with a fourth metatarsal, which showed signs of fast growth and what appears to be an External fundamental System (EFS). This doesn't seem to match the growth trajectory of Allosaurus, thus the authors separate Saurophaganax from Allosaurus. That is, if "the appositional rate of the metatarsal is representative of the whole animal." However, it's the last conclusion that floored me. The authors stated that the Saurophaganax vertebral elements (atlas and dorsal vertebrae, and the caudal chevrons) belonged to sauropods and not theropods! In fact, they might belong to an already established sauropod taxon. The holotype of Saurophaganax is the mid-dorsal neural arch (dorsal vertebra) (Chure, 1995, pp. 104 and 106). Based on Danison et al., (2024), this would make Saurophaganax a sauropod or a synonym of another sauropod! The name "Saurophaganax" might not even exist anymore... The skull and limb/long bone elements, said to have belonged to Saurophaganax, do resemble theropoda though. In particular, they are "largely consistent with Allosaurus." (SVP, 2024, pp. 164-165).

Danison et al., (2024 [SVP, 2024]):
P. 164:

P. 165:

Honestly, I don't know what to think. I was certain that the Saurophaganax material belonged to a  carcharodontosaurid. However, some of the bones did resemble Allosaurus, like the giant humerus OMNH 01935. Chure (1995) said that the bone was "robust," yet "closely resembles that of Allosaurus," (p. 103). Smith (1998) said that the humerus matched the Allosaurus growth chart and "non-size-related variation," despite being large (pp. 131, 134, 138-139). In fact, Smith said that the Saurophaganax material "lies on the same growth trajectory for Allosaurus in almost every case," (p. 140). I've also noted before that OMNH 01935 is morphologically indistinct from other humeri of Allosaurus. Saurophaganax was more of a chimera than people thought. Heck, I originally asserted that Saurophaganax was a chimera (half carcharodontosaurid and half Allosaurus) until I discovered that other carcharodontosaurid taxa had similar bones to it, excluding OMNH 01935. The giant humerus still confused me, but I still thought that it belonged to Allosaurus. I still think that. In fact, aside from (possibly) the fourth metatarsal and the vertebrae, other postcrania bones resemble Allosaurus', according to Danison et al., (2024). 

I decided to see if it was possible for the "Saurophaganax" atlas to resemble a sauropod's atlas, or not. I saw Apatosaurus louisae's atlas, and... Yeah, they look really similar:

Apatosaurus louisae's atlas and axis ("at" is atlas) (Gilmore, 1936, p. 192):

"Saurophaganax's" atlas (OMNH 01135) (Chure, 1995, p. 104):

"Saurophaganax" was a chimera after all... I truly believe that some Allosaurus bones got jumbled up in the skeletal material. Now, it seems that some Allosaurus AND probably some sauropod bones got mixed in there as well. I wonder if there's any actual "Saurophaganax" material left to keep the taxonomic name alive?

I'm not going to make any final conclusions until the authors finish their paper. I want to give them a chance, and go about this with an open mind. If this is the end of "Saurophaganax,' then so be it. It was a lot of fun to research the animal. 

Links:
Danison et al., (2024) (SVP, 2024, pp. 164-165):
https://vertpaleo.org/wp-content/uploads/2024/10/2024_SVP_Program_Final3.pdf
Gilmore (1936) (P. 192):
https://www.biodiversitylibrary.org/page/53145444#page/254/mode/1up
Chure (1995):
https://www.researchgate.net/publication/230892243_A_reassessment_of_the_gigantic_theropod_Saurophagus_maximus_from_the_Morrison_Formation_Upper_Jurassic_of_Oklahoma_USA
Smith (1998):
https://www.researchgate.net/publication/272151969_A_morphometric_analysis_of_Allosaurus

(News) Nanotyrannus holotype was an adult (Griffin et al., 2024)!

Nanotyrannus/Dryptosaurus lancensis holotype CMNH 7541 (Dalman et al., 2018, p. 135 Figure 15):

One of the biggest critiques against Nanotyrannus/Dryptosaurus lancensis being a valid taxon was that all the specimens were apparently juveniles. As a result, they must've been juvenile Tyrannosaurus rex specimens because no juvenile T. rex specimens have been discovered. However, it has been stated numerous times now that most of the N./D. lancensis specimens were actually slow-growing individuals that were close to maturity, and not fast-growing juvenile T. rex specimens. Now, we have an actual adult N./D. lancensis specimen and it was hiding in plain sight the entire time: CMNH 7541!

CMNH 7541 is the holotype specimen of N./D. lancensis. For the longest time, people thought that it was a hatchling at 8 years of age (Erickson et al., 2006, Supplementary Materials, p. 13) (Carr, 2020, Figures 2 and 12). Some people even labelled the specimen as a nomen dubium (Paul, 2022, p. 67 [Preprint]). Now, it turns out that the real age of the specimen was almost double of that! Griffin et al., (2024), an abstract from SVP 2024, studied the hyoid of CMNH 7541, along with other extinct and extant animals. The hyoid of CMNH 7541 revealed that the specimen was about 14 years old (14 LAGs "at minimum" were present in the hyoid), along with extensive (Haversian) remodeling and secondary osteons within the bone itself. The best part was that an EFS marker was found within the "outermost cortex" of the hyoid. The authors concluded that, although they're not throwing out the possibility that CMNH 7541 couldn't have been a T. rex, the best conclusion based on the evidence is that CMNH 7541 was a distinct taxon of "tyrannosaurid" that was "fully grown," (Abstract [SVP, 2024, pp. 232-233]).

Griffin et al., (2024) (SVP, 2024):
P. 232:

P. 233:

The EFS, or External Fundamental System, indicates that an individual was mature at the time of death. Neither the 13-year old N./D. lancensis specimens BMRP 2002.4.1 ("Jane"), or the 15-year old BMRP 2006.4.4 ("Petey"), had the EFS in their limb bones (Woodward et al., 2020, p. 4). Neither does "Zuri," but "Zuri's" growth was slowing down and wasn't a juvenile despite being "at minimum 12-13 years old when it died." "Zuri" also had extensive Haversian remodeling in its bones as well (Griffin, 2014, Abstract). Both "Jane" and "Petey" were also slowing down in their growth, and they didn't fit in the Tyrannosaurus growth trajectory pattern (Jevnikar and Zanno, 2021, Abstract [SVP, 2021, p. 151]) (Longrich and Saitta, 2024, pp. 38-39). Longrich and Saitta (2024) also said that "Zuri" "was apparently near full size when it died," (p. 39). CMNH 7541, although being 14 at least, has the EFS present in its hyoid (Griffin et al., 2024, Abstract [SVP, 2024, pp. 232-233]). It seems that N./D. lancensis aged extremely quickly, and died young. Other basal tyrannosauroids that did something similar were the basal pantyrannosaurian Dilong (Xu et al., 2004, p. 680), and the eutyrannosaurian Raptorex (Sereno et al., 2009, p. 419; Supplementary Materials, p. 2). This is interesting, since I believe that Nanotyrannus/Dryptosaurus lancensis was also a basal eutyrannosaurian. Dryptosaurus aquilunguis, and Appalachiosaurus/Dryptosaurus montgomerensis, were also eutyrannosaurians (see Delcourt and Grillo, 2018).

This is amazing! I contacted Mr. Griffin back in 2021 regarding "Zuri." He was leaning towards N./D. lancensis being a juvenile T. rex at that time. I was doing so as well, even though I had my doubts. Now, his work is helping to demonstrate that the opposite is true. He actually helped to find an adult N./D. lancensis! Congratulations to him, and his team!

We finally have an adult Nanotyrannus/Dryptosaurus lancensis!

Links:
Griffin et al., (2024) (SVP, 2024, pp. 232-233):

https://vertpaleo.org/wp-content/uploads/2024/10/2024_SVP_Program_Final3.pdf

University of Bath (2024):
https://www.bath.ac.uk/announcements/new-research-shows-juvenile-t-rex-fossils-are-a-distinct-species-of-small-tyrannosaur/

Dalman et al., (2018):

https://www.researchgate.net/publication/328676947_TYRANNOSAURID_TEETH_FROM_THE_UPPER_CRETACEOUS_CAMPANIAN_TWO_MEDICINE_FORMATION_OF_MONTANA

Erickson et al., (2006):

https://www.researchgate.net/publication/6944402_Tyrannosaur_Life_Tables_An_Example_of_Nonavian_Dinosaur_Population_Biology

-Supplementary Materials (PP. 13-14):
http://science.sciencemag.org/content/sci/suppl/2006/07/11/313.5784.213.DC1/Erickson.SOM.pdf

Carr (2020) (Figures 2 and 12):
https://peerj.com/articles/9192/

Woodward et al., (2020):

https://www.researchgate.net/publication/338331660_Growing_up_Tyrannosaurus_rex_Osteohistology_refutes_the_pygmy_Nanotyrannus_and_supports_ontogenetic_niche_partitioning_in_juvenile_Tyrannosaurus

Jevnikar and Zanno (2021) (SVP, 2021, p. 151):

https://vertpaleo.org/wp-content/uploads/2021/10/SVP_2021_VirtualBook_final.pdf

Paul (2022) (Preprint):

https://www.biorxiv.org/content/10.1101/2022.08.02.502517v1.full

-V2 (PDF):

https://www.biorxiv.org/content/10.1101/2022.08.02.502517v1.full.pdf

Longrich and Saitta (2024):
https://www.mdpi.com/2813-6284/2/1/1
Griffin (2014):
-Abstract:
https://www.semanticscholar.org/paper/Using-Osteohistology-to-Determine-the-Taxonomic-of-Griffin/149cadc7cd0f9aa4b55d77810a818ab59b040417
-Full:
https://digitalcommons.cedarville.edu/cgi/viewcontent.cgi?article=1136&context=research_scholarship_symposium

Xu et al., (2004):

https://www.researchgate.net/publication/8246151_Basal_tyrannosauroids_from_China_and_evidence_for_protofeathers_in_tyrannosauroids
Sereno et al., (2009):

https://www.researchgate.net/publication/26820186_Tyrannosaurid_Skeletal_Design_First_Evolved_at_Small_Body_Size

-Supplementary Materials:

https://www.science.org/doi/10.1126/science.1177428

V2:

https://d3qi0qp55mx5f5.cloudfront.net/paulsereno/i/docs/09-SCI-Raptorex-SOM.pdf?mtime=1591813921

Delcourt and Grillo (2018):

https://www.sciencedirect.com/science/article/abs/pii/S0031018218302566

-Phylogenetic chart:

https://images.app.goo.gl/wFSumFkc5vq7WGi28