My Prehistoric Saga: 2020

Thursday, November 19, 2020

Size Calculations for Crocodyliformes:

The Percentage Increase/Decrease Method:
1. Take new number and subtract it from original number.
2. Take that number and divide it by the original number and multiply by 100.
3. That number will by your percentage increase or decrease if it's negative.

Ex.: "Stan's" Femur is 130 and has a body length of 12.2 meters. "Wyrex" has a femur length of 132.7 cm.

132.7 - 130 = 2.7.
2.7 divided by (represented by "/") and multiplied by (represented by "*") equals 2.1.
(2.7/130*100 = 2.1)
2.1 is your percentage increase, or 2.1% increase.
12.2 m + 2.1% = 12.5 meters for "Wyrex."

Links:
Percentage Increase/Decrease Method Links:
"Percentage Change - Percentage Increase and Decrease." SkillsYouNeed:

https://www.skillsyouneed.com/num/percent-change.html
"Relative Increase." percentage.calculators.ro:
https://percentages.calculators.ro/15-percentage-increase-from-original-number-to-new-value.php

Model: Florida Alligator:
Skull: 26 cm (10 1/4 inches).
Body: 6 feet.

Link:
Worldwide Wildlife Products. "Alligator Skulls": "10-1/4 Alligator Skull":
https://www.worldwidewildlifeproducts.com/store/pc/10-1-4-inches-Good-Quality-Florida-Alligator-Skull-for-Sale-You-are-buying-this-one-for-59-99-125p7589.htm

1. Cerrejonisuchus:

Skulls (Largest): 31.4 cm (Table 1).

26 - 31.4 = 5.4.

5.4/26*100 = 20.8% increase.

1.829 m + 20.8% = 7 feet (2.2 meters).

Cerrejonisuchus' Total Length: 7 feet (2.2 meters).

Link:

https://www.tandfonline.com/doi/full/10.1080/02724630903409204

2. Eothoracosaurus:

MSU 3293:
Skull: 89.7 cm (For now).

Cerrejonisuchus:

Skulls (Largest): 31.4 cm.

Body: 2.2 meters.

89.7 - 31.4 = 58.3.

58.3/31.4*100 = 185.7% increase.

2.2 m + 185.7% = 21 feet (6.3 meters).

Eothoracosaurus' Total Length: 21 feet (6.3 meters).

Links:

Carpenter (1983) (Pg. 4 Table 1 [24-33]):

https://www.mdeq.ms.gov/wp-content/uploads/2013/10/Vol_4_1.pdf

Species Name:
Brochu (2004): https://www.researchgate.net/publication/40662929_A_new_Late_Cretaceous_gavialoid_crocodylian_from_eastern_North_America_and_the_phylogenetic_relationships_of_Thoracosaurs

Link 2:

https://www.jstor.org/stable/4524750?seq=1

Time:

Fossilworks. "Eothoracosaurus":

http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=176554

Fossilworks. "Eothoracosaurus mississippiensis":

http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=176555

Family Tree:
Lee and Yates (2018) (Figure 1):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6030529/

3. Elosuchus:
Carcharodontosaurus and Elosuchus by David Bonadonna:

Largest Skull: 107.7 cm (Meunier and Larsson, 2017, Table 1).

Eothoracosaurus:

Skull: 89.7 cm.

Body: 6.3 m.

107.7 - 89.7 = 18.

18/89.7*100 = 20.1% increase.

6.3 m + 20.1% = 25 feet (7.6 meters).

Elosuchus' Total Length: 25 feet (7.6 meters).

Link:
Meunier and Larsson (2017) (Table 1):
https://academic.oup.com/zoolinnean/article/179/1/169/2870024
Picture:
David Bonadonna:
http://www.davidebonadonna.it/project/342/

4. Sarcosuchus:
Sarcosuchus vs. Suchomimus:

1. MNN 604:

Skull: 150 cm (Sereno et al., 2001, pg. 1518 Table 1).

Elosuchus:

Skull: 107.7 cm.

Body: 7.6 meters.

107.7 - 150 = 42.3.

42.3/107.7*100 = 39.3% increase.

7.6 m + 39.3% = 35 feet (10.6 meters).

Link:
Sereno et al., (2001) (Pg. 1518 Table 1):

https://www.researchgate.net/publication/11672584_The_Giant_Crocodyliform_Sarcosuchus_from_the_Cretaceous_of_Africa

2. BC-156:
Skull: 172.7 cm (Bone Clones).

Deinosuchus:

Skull: 167.6 cm.

Body: 11.8 m.

167.6 - 172.7 = 5.1.

5.1/167.6*100 = 3% increase.

11.8 m + 3% = 40 feet (12.2 meters).

Link:
Bone Clones:

https://boneclones.com/product/sarcosuchus-imperator-supercroc-skull-BC-156
Time Period:
Barremian and Older:
Douiret Formation:
Loeuff et al., (2010) (Pg. 753-754, 756-757):
http://doc.rero.ch/record/293777/files/S0016756810000178.pdf
El Rhaz Formation:
Bertozzo et al., (2017) ("Introduction"):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5480399/
Loeuff et al., (2012) (Pg. 3 and 8):
https://www.researchgate.net/publication/284617900_Between_Tendaguru_and_Bahariya_on_the_age_of_the_Early_Cretaceous_dinosaur_sites_from_the_Continental_Intercalaire_and_other_African_formations
Others:
Souza et al., (2019) (Pg. 2-3, and 5):
https://paleontologia.ufes.br/sites/paleontologia.ufes.br/files/field/anexo/souza_et_al._2019_-_sarcosuchus_0.pdf
Barremian-Aptian:
Contessa, Michela. Paleontological studies of Cretaceous vertebrate fossil beds in the Tataouine Basin (southern Tunisia). Pg. 12-13. 2013:
http://amsdottorato.unibo.it/5240/1/Contessi_Michela_tesi.pdf

Aptian-Albian:
Dridi (2018):
https://www.sciencedirect.com/science/article/pii/S1464343X18301778?via%3Dihub
Albian:
Contessa, Michela. Paleontological studies of Cretaceous vertebrate fossil beds in the Tataouine Basin (southern Tunisia). 2013:
http://amsdottorato.unibo.it/5240/1/Contessi_Michela_tesi.pdf
Notes:
Age:
Pg. 14: Albian.
Fossils:
All: Pages 20-29; Sarcosuchus: Pg 25-26, 28; Spinosaurus, Carcharodontosaurus, and ornithopod: Pg 27-29).

Sarcosuchus' Total Length: 35-40 feet (10.6-12.2 meters).

5. Deinosuchus:
Deinosuchus vs. Albertosaurus or Gorgosaurus:

Skull: 5.5 feet/5 feet 6 inches (167.6 cm) (Prehistoric Planet Store) (Bay State Replicas).

Sarcosuchus holotype:

Skull: 150 cm.

Body: 10.6 m.

150 - 167.6 = 17.6.

17.6/150*100 = 11.7% increase.

10.6 m + 11.7% = 39 feet (11.8 meters).

Deinosuchus' Total Length: 39 feet (11.8 meters).

Link:
Prehistoric Planet Store:

http://www.prehistoricstore.com/item.php?item=1475

Bay State Replicas:

http://www.baystatereplicas2.com/product/deinosuchus-skull/

6. Purussaurus:

Skull (Mandible): 175 cm (Aureliano et al., 2015, "Introduction" p. 4).

Sarcosuchus Specimen 2:

Skull: 172.7 cm.

Body: 12.2 m.

175 - 172.7 = 2.3.

2.3/172.7*100 = 1.3% increase.

12.2 m + 1.3% = 41 feet (12.4 meters).

Purussaurus' Total Length: 41 feet (12.4 meters).

Link:
Aureliano et al., (2015) ("Introduction" p. 4):

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0117944

7. Stomatosuchus:
Skull from Paleofile:

Skull: 2 meters (Stromer, 1925, pg. 1) (Stromer, 1933, pg. 45).

Purussaurus:

Skull (Mandible): 175 cm.
Body: 12.4 meters.

175 - 200 = 25.

25/175*100 = 14.3% increase.

12.4 m + 14.3% = 47 feet (14.2 meters).

Stomatosuchus' Total Length: 47 feet (14.2 meters).

Links:
Stromer (1925) (Pg. 1):

https://www.zobodat.at/pdf/Abhandlungen-Akademie-Bayern_30_0001-0022.pdf

Stromer (1933) (Pg. 45):

https://www.zobodat.at/pdf/Abhandlungen-Akademie-Bayern_NF_15_0001-0055.pdf
Skull Pic:
Paleofile:
https://images.app.goo.gl/uwizbwGoJxtrJgsNA

Saturday, September 19, 2020

Letting Go of Jurassic Park/World.

PS: This is the first post that I've written with the new Blogger interface. It looks terrible, but hopefully I'll get the hang of it soon.

Update (12/17/21): I finally got the hand of this new interface!

This is a rewritten post that I made some time ago. I feel like I could make this a better post, and get my feelings out better this time.

I love Jurassic Park. It helped my love of dinosaurs to grow, and it's one of the reasons why I'm trying to get into paleontology. It also takes me back to a time when I was a kid. I didn't have great interactions with people, so I got lost in films and television shows. The Jurassic Park franchise, in particular the first two films: Jurassic Park (1993) and The Lost World Jurassic Park (1997), gave me some of my favorite memories that I had as a kid. They made me wonder what it would be like to see dinosaurs alive. It also taught me that there are some things in science that mankind should not mess with, and that's coming from a university student going into biology. Unfortunately, my love for this franchise has dwindled.

It started when I found YouTube, and started watching people who review movies. People who reviewed the Jurassic Park franchise always praise the first film. When it comes to the first two sequels, The Lost World Jurassic Park (1997) and Jurassic Park III (2001), people either hate them both, or like one of them over the other. When Jurassic World (2015) came out, there were who said that it was the best sequel to the first film. I remember thinking that the film was alright, but the climatic final battle was cool! It wasn't entirely what I hoped it would be, but I'll discuss that further below. People were/are split on Jurassic World Fallen Kingdom (2018), but I think it's the third best Jurassic film. Jurassic World is after that. Jurassic Park III is in last place.

With Jurassic World Dominion (2022) coming up in the summer of 2022, and with what has been released so far concerning the film, I must say that I have come to a point where I must let go of Jurassic Park. These are my reasons why:

1. Jurassic Park III.

I remember when I learned that there was a third Jurassic Park film. When my mother, grandmother, and I sat in the living room to watch it, I remember that it left a horrible taste in my mouth. The biggest reason is that the T. rex, the original alpha theropod and symbol of the franchise, was killed at the hands of the Spinosaurus, and it never showed up again. As a result, the film was... I guess you can say, less interesting. It was a tonal shift for me because it didn't feel like Jurassic Park, despite having Dr. Grant back, and Dr. Sattler too for a little bit. The VHS copy of the film didn't even have the T. rex skeleton on the title. It was the Spinosaurus'. This was the first time that I learned to hate a dinosaur, and it took a LONG time for me to get over this. I wasted so many years online trying to make Spinosaurus look as pitiful as possible, but I couldn't see how pointless it was. In Jurassic Park/World, the larger theropod always beats the smaller theropod, regardless of scientific accuracy. This continued with Jurassic World, but I'll get to that later. I hated the real Spinosaurus because a fictitious version of it killed my favorite dinosaur, T. rex, which is also a fictitious version of the real T. rex. I don't hate Spinosaurus anymore, and I'm so sad that it took me so long to reach this point.

Another reason why, even though I didn't know this until I grew older, I didn't like JPIII was that Dr. Grant and Dr. Sattler were separated. In the first film, the ending hinted that the two of them were going to start a family. In the third film, Dr. Sattler has a family with some other dude that I didn't, and still don't, care about. Breaking up couples seems to be a trend nowadays, and I HATE IT! Just let the characters have a happy ending! Dr. Grant and Sattler will be back in Dominion, so let's see what their relationship will be like. I highly doubt that they'll be back together.

2. The final battle of Jurassic World.
Jurassic World came about fourteen years after Jurassic Park III. A part of me hoped that it would fix the mistakes that JPIII made, and restore the T. rex to its rightful position as the mascot of the franchise. However, it will only confirm to me how pathetic the T. rex is in this franchise now.

The Indominus rex was the new dinosaur villain in the film. When the original T. rex from the first film, now nicknamed "Rexy" by the fans, appeared to take on the I. rex, I was hoping that she would kill the I. rex single-handedly, this redeeming the T. rex in the franchise. After getting a few bites into the I. rex, the Indominus made short work of "Rexy." I was in denial for years before I finally saw reason: "Rexy" would have DIED if "Blue" the Velociraptor (actually a Deinonychus) didn't rescue her from the Indominus. What hurt me the most was that we didn't see "Rexy," or many other actual dinosaurs, throughout the film aside from cameos, and when we finally see "Rexy," she gets beaten by the Indominus in about thirty seconds. This is also the same amount of time that it took for the Spinosaurus to kill the T. rex in JPIII. We also didn't see other dinosaurs for the most part unless they were getting killed off by the Indominus rex. Only the Velociraptor pack were shown predominantly throughout the film, and it became a little annoying.

3. Too much focus on Velociraptors.
I love dromaeosaurs, but having them shown almost all the time in these movies is becoming a little annoying. This is one of the reasons why I love The Lost World Jurassic Park so much. The T. rex pack was shown as being the major threat on Sorna, and we saw the bull T. rex rampage through San Diego! Having the T. rex being the main threat made so much more sense to me than the Velociraptors, even though the Velociraptors from the first two films are my favorite iterations. In JPIII, the Velociraptors looked cool but they were treated as "super dinosaurs." They were "smarter than primates," as Dr. Grant said in the film. Even when I was a kid, I thought that was ridiculous. Funnily enough, the Velociraptors were the dinosaurs that actually got close enough to almost kill Dr. Grant and the other human protagonists in the film (near the end).

This got worse in Jurassic World, and Jurassic World Fallen Kingdom. In Jurassic World, "Blue" and her pack did more damage to the Indominus rex than "Rexy" ever did, and "Blue" had to save "Rexy" from being killed by the I. rex! In Fallen Kingdom, "Blue" killed the new dinosaur villain, the Indoraptor, all by herself, albeit with the help of a Triceratops skull replica, but "Blue" didn't suffer any damage during the fight. That's really hard to believe because the Indoraptor was a super Velociraptor, so it should have beaten "Blue" like the Indominus rex, a super T. rex, beat "Rexy." Nope! "Blue" is just fine. "Rexy" in Fallen Kingdom barely did anything aside from killing a Carnotaurus, which a lot of fans didn't like (except for me, of course, and Carnotaurus is my second-favorite dinosaur), and killing Eli Mills, the human antagonist of the film. Compare that to "Blue" killing the Indoraptor without getting tossed like a bad habit like "Rexy" did in the previous film by the I. rex. The Indominus rex slammed "Blue" into a brick wall, and she comes out unscathed in order to rescue "Rexy." Then in Fallen Kingdom, "Blue" beats the Indoraptor without "Rexy's" help. The Velociraptors have been overused, and they are invincible!

I must note that "Blue" and "Rexy" did not kill the Indominus rex themselves. The Mosasaurus killed the Indominus rex. This would make the Mosasaurus the new icon of Jurassic World. I believe that it could beat the T. rex, Indominus rex, Giganotosaurus, and even the Spinosaurus, in a fight.

4. "Rexy" the T. rex being murdered 66 million years ago by the Giganotosaurus.

As if the Spinosaurus and Indominus rex weren't bad enough. Now, we have the Giganotosaurus. The Giganotosaurus is the new big bad dinosaur of Dominion (what a surprise). In a sneak peek for the film, we see "Rexy" and the Giganotosaurus square off, and of course, the Giganotosaurus breaks "Rexy's" neck and kills her! Shades of JPIII... Now, this took place 66 million years ago in the film. In real life, Giganotosaurus didn't coexist with T. rex. Giganotosaurus lived in South America. Tyrannosaurus lived in North America (and Eurasia, based on my own interpretation). However, this doesn't matter when it comes to Jurassic Park/World.

The reason why the T. rex keeps getting the short end of the stick is because they have to make the other theropods look strong. In return, this makes the T. rex look extremely weak. The T. rex hasn't beaten another large theropod in the franchise at all. It can beat smaller (Velociraptors), and medium-sized (Carnotsaurus) theropods, but it's a chump compared to larger theropods like the Spinosaurus, Indominus rex, and Giganotosaurus. If we were being scientifically accurate, the T. rex would have beaten the Spinosaurus and Giganotosaurus. The Indominus rex is an imaginary dinosaur, a hybrid made up of a T. rex, Velociraptor, and a conglomerate of other animals. Therefore, it's easy to see how it could beat the other theropods. Only the Spinosaurus, I think would give the I. rex a fair fight. The Indoraptor is also a hybrid of a Velociraptor, and other animals. This is why I don't get how "Blue" was able to fend off the Indoraptor so easily... However, scientific accuracy probably wouldn't make for a good story, or action scene. This is why I think the T. rex is a joke now, and I don't expect "Rexy" to beat the Giganotosaurus in the rematch on her own, later on in the film. She's going to need help, either from "Blue" again, or from the Spinosaurus who has yet to come back into a new JW film.

Conclusion.
This is why I will never see Jurassic Park/World the same way ever again. Despite what people may feel towards The Lost World Jurassic Park, the first two films will always be my favorites and The Lost World is the best sequel. I want to love the other films as well, but they always fall short compared to the first two films. The T. rex will never be on top ever again, and I can't hold that against any other theropod that beats the T. rex in the franchise. They're just doing what the filmmakers wants them to do. In all honesty, the Mosasaurus is the top predator of the franchise now. Dr. Grant and Sattler are not together anymore, and it's more than likely that they will not be together in Dominion. I also cannot get emotionally invested in anything else that happens in this franchise again. It'll drive me crazy if I do. I do not have any creative control in the franchise, so whatever happens next is in the hands of the filmmakers. If I want the T. rex to be the alpha theropod again, then I would have to write the story myself.

So long, Jurassic Park/World. I will never forget the great memories you gave me with the first two films.

Saturday, August 22, 2020

What If: A Giant Sauropod (Argentinosaurus?) from the Candeleros Formation.

For the second post in my "What If" series, I'll be discussing whether or not Argentinosaurus actually lived in the Candeleros Formation.

Argentinosaurus from Dinosaurs: Giants of Patagonia:

Like I mentioned before in my "Were Giganotosaurus and Mapusaurus the Same Genus?" post, I was told, and read, some things about Giganotosaurus and Mapusaurus that contradicted each other over the years. After examining the two animals' skeletons, and looking up how old their formations are, I've come to three conclusions:

1. Mapusaurus (10.9-15.3 meters) is bigger than Giganotosaurus (12.4-13.1 meters). This makes sense because, back in the day, I read that Giganotosaurus didn't coexist with Argentinosaurus, and that it hunted smaller titanosaurs (despite being 13.2 meters long). Mapusaurus was the carcharodontosaurid that coexisted with Argentinosaurus, despite being 10.2 meters long. Why would a carcharodontosaurid, which evolved after a larger carcharodontosaurid, get smaller in order to hunt a larger animal? Now I know that isn't the case. We'll get back to Argentinosaurus shortly.

2. Giganotosaurus and Mapusaurus seem to have coexisted, based on microfossils discovered, and U-Pb dating done, in the Candeleros and Huincul Formations.

3. Mapusaurus roseae seems to be a species of Giganotosaurus: Giganotosaurus roseae. I mainly go with Giganotosaurus (Mapusaurus) roseae.

Now, we'll talk about Argentinosaurus again. Back when I thought that Giganotosaurus was bigger than Mapusaurus, I was perplexed when I read/was told that Giganotosaurus hunted Andesaurus, not Argentinosaurus. It confused me because Andesaurus was only 80 feet long (24.4 meters). This is small compared to the 170-foot long (51.8 meters) Argentinosaurus. I asked myself this question for years: How could the larger Giganotosaurus hunt such a smaller sauropod, while the smaller Mapusaurus hunted a bigger sauropod? Nowadays, with a larger size for Mapusaurus, along with the possibility of Mapusaurus roseae being Giganotosaurus roseae, based on my analysis, I don't fret over this question anymore. This is not the end of the story though.

A couple of years ago now, I read in Calvo (1999) about the bones of a large sauropod, called Sauropoda gen. et sp. indet., discovered in the Candeleros Formation, which is the same formation that Giganotosaurus carolinii came from. Labelled as MUCPv-251, it consisted of a possible dorsal vertebra and rib. It seems to have come from a large sauropod, and Calvo says that it might be related to Argentinosaurus (pg. 26).

Statement on the specimen from Calvo (1999) (P. 26):

Info. on MUCPv-251 from Calvo (1999) (Pg. 26):

-Consists of a dorsal vertebra and rib.
-Rib is 175 cm long, but it's partial/the proximal half. ("Proximal" means closer to the body, as explained by Merriam-Webster and Lexico)
-Width at proximal end: 21 cm.
-Width at distal end: 12 cm.

-Rib is probably a dorsal, but I'm making that assumption because Calvo says that the vertebra found with the rib is probably a dorsal.
-Calvo thinks there's a possibility that these bones could be related with Argentinosaurus. However, I can't find any other papers that talk about this specimen.

Last year or so, I tried to find a way to estimate a length for this animal, but I couldn't find one. I was use to estimating dinosaur lengths based on limb and skull bones, not ribs. However, using the bones of the Chinese titanosaur Ruyangosaurus, I was able to get a size estimate for MUCPv-251.

Size Estimates for MUCPv-251:

1. Proximal Part of Rib Length:

Ruyangosaurus:

Dorsal Rib Length: 127 cm (proximal portion) (Sassani and Bivens, 2017, pg. 8).

Length: 47.1 meters.

127 - 175 = 48.

48/127*100 = 37.8% increase.

47.1 m + 37.8% = 213 feet (64.9 meters).

Hypothetically Complete Rib for Ruyangosaurus:
"Huangetitan" ruyangensis' Largest Dorsal Rib Length: 293 cm (Sassani and Bivens, 2017, pg. 28).
Width: 17.2 cm (Sassani and Bivens, 2017, pg. 15).

Ruyangosaurus' Dorsal Rib Width: 18 cm (Sassani and Bivens, 2017, pg. 15).

Dorsal Rib Length (Proximal half only): 127 cm (Sassani and Bivens, 2017, pg. 8).
Body Length: 47.1 meters.

17.2 - 18 = 0.8.
0.8/17.2*100 = 4.7% increase.
293 cm + 4.7% = 306.8 cm for Ruyangosaurus' complete dorsal rib.

Hypothetically Complete Rib for MUCPv-251:

Ruyangosaurus:

Dorsal Rib Length (Complete): 306.8 cm.
Width: 18 cm (Sassani and Bivens, 2017, pg. 15).

Length: 47.1 meters.

21 - 18 = 3.
3/18*100 = 16.7% increase.
306.8 + 16.7% = 358 cm for MUCPv-251's complete dorsal rib.

2. Hypothetically Complete Rib Length:

Ruyangosaurus:

Dorsal Rib Length (Complete): 306.8 cm.
Width: 18 cm (Sassani and Bivens, 2017, pg. 15).

Length: 47.1 meters.

306.8 - 358 = 51.2.
51.2/306.8*100 = 16.7% increase.
47.1 m + 16.7% = 181 feet (55.0 meters).

MUCPv-251's Total Length: 181 feet (55.0 meters).

Is MUCPv-251 Argentinosaurus?
Now that we have a size estimate for MUCPv-251, the question we have to ask now is whether or not MUCPv-251 belongs to Argentinosaurus, let alone a titanosaur? Based on the sauropod fauna discovered in the Candeleros Formation, consisting on the titanosaurs Andesaurus (80 feet long; 24.4 meters) and MMCH-Pv 47 (81 feet; 24.7 meters), and the rebbachisaur Limaysaurus (71-84 feet; 21.5-25.6 meters). Limaysaurus was bigger than the two titanosaurs, but its ribs were small.

Limaysaurus Skeleton:

I think the size of MUCPv-251 seems to put it in the titanosaur family. The width of the rib matches the widths of the titanosaurs Ruyangosaurus' and "Huangetitan" ruyangensis' rib widths. In fact, MUCPv-251's rib width was larger than both of them. Width aside, the size of this animal's bones puts it up there with Argentinosaurus! Argentinosaurus was 167 feet long (51.8 meters). Based on my estimates, MUCPv-251 was 181 feet long (55.0 meters). It was larger than Argentinosaurus!

Argentinosaurus was the largest titanosaur from South America. However, no Argentinosaurus fossils were discovered in the Candeleros Formation... As far as I know. However, MUCPv-251 seems to suggest that this might not be the case. What we do know is that its bones belong to a sauropod, as stated in Calvo (1999). Based on the size of the bones, the animal seems to have been a titanosaur. It might not be too

crazy to say that this animal was Argentinosaurus. A couple of sauropod dinosaurs from the Candeleros and Huincul Formations were found in other formations. Limaysaurus was discovered in both the Candeleros and Huincul Formations (Calvo and Salgado, 1995, pg. 15). Andesaurus was discovered in the Candeleros (Calvo, 1999, pg. 16, 22-24) (Calvo and Salgado, 1995, pg. 14), but also in the Bajo Barrea Formations. A titanosaur caudal vertebra was discovered there that has been attributed to Andesaurus (Casal et al., 2016, pg. 57). The Bajo Barrea Formation has been dated from the Albian-Turonian (Casal et al., 2009, "Abstract," "Introduction" p. 1). Pollen and spore samples assigned it to the Albian-Cenomanian, but radiometic dating (Ar/Ar), and U-Pb dates, place it at 99-91 million years (Casal et al., 2016, pg. 56, "Edad de la Formacion Bajo Barreal"). Therefore, the Bajo Barrea Formation is 113-90 million years old (Albian-Turonian), and so is Andesaurus. Therefore, we cannot throw out the possibility that MUCPv-251 could be the first fossils of Argentinosaurus from the Candeleros Formation.

Based on microfossils and U-Pb dating, the Huincul Formation was also Albian-Cenomanian in age (Vallati (2001) ("Abstract") (List of Microflora), Vallati (2006) ("Abstract"), Musacchio and Vallati (2007) ("Introduction"), and Vallati (2013) ("Paleotropical representatives in Northern Patagonia" 1-1.2, "Conclusions") (Corbella et al., 2004, "Abstract," "Characteristics and radiometric age of the tuff bed" pg. 229) (Garrido, 2010, pg. 138), just like the Candeleros Formation (Baez et al., 2000, pg. 491, "Geological Setting") (David Cannatella, 2015, "Temporal Data: Ages of Fossils and Calibration Priors," p. 20) (Tunik et al., 2010, pg. 270-271) (Di Giullo et al., 2012, pg. 600 "Results") (Garrido, 2010, pg. 134) (Halupczok et al., 2017, "Geological setting" pg. 2). The time frame of both formations makes it even more likely that MUCPv-251 could actually be Argentinosaurus.

The only other titanosaurs from the Candeleros Formation is Andesaurus and MMCH-Pv 47. Andesaurus is probably too small to be the real genus, but we only have one specimen to demonstrate this (Mannion and Calvo, 2011, "Additional Remains Referred To Andesaurus" p. 3). Perhaps Andesaurus grew larger than we've previously thought? I would like to think so, but this cannot be verified. Based on the skeleton we have now, Andesaurus is too small to be the real genus of MUCPv-251. MMCH-Pv 47 is slightly larger than Andesaurus, but we only have its vertebrae and no ribs. MMCH-Pv 47 is an unidentified titanosaur as well, so maybe comparing MUCPv-251 to it wouldn't be the best choice. Along with that, I cannot compare the specimens either way because I don't have a picture of MUCPv-251's bones. All I have are the size and width of its dorsal width. Therefore, based on the size, and width, of the bones, perhaps MMCH-Pv 47 isn't the real genus either. It's still small compared to Argentinosaurus.

Since I cannot find any other sources on MUCPv-251 other than Calvo (1999), I will place it as a titanosaur. Based on the size of the bones, this could possibly be the oldest recorded specimen of Argentinosaurus.

Update (2/4-9/21): A new large titanosaur has been discovered in the Candeleros Formation! Based on the size of the 166-cm long pubis, the animal was 170 feet long (51.7 meters), with a wider range of 119-207 feet (36.2-63.1 meters) based on the coracoid. Whether or not this mystery titanosaur is the owner of MUCPv-251 is unknown, but it's a possibility. However, this new titanosaur, catalogued as MOZ Pv 1221, proves that Giganotosaurus carolinii lived alongside massive sauropods!

As to whether or not MOZ is Argentinosaurus, the authors say that they don't know. Argentinosaurus is extremely fragmentary, so more MOZ bones will have to be excavated to see if it is a specimen of Argentinosaurus ("Discussion" para. 4):

There might be hope yet that MOZ is Argentinosaurus, and that Argentinosaurus coexisted with Giganotosaurus. However, that question will have to remain open.

Links on MOZ Pv 1221:
https://psdinosaurs.blogspot.com/2021/01/giant-titanosaurs-40-tons-or-more.html
Size:
https://psdinosaurs.blogspot.com/2018/12/size-calculations-for-herbivorous.html

Links:
Calvo (1999) (Pg. 26):
https://www.researchgate.net/publication/284053211_Dinosaurs_and_other_vertebrates_of_the_Lake_Ezequiel_Ramos_Mexia_Area_Neuquen-Patagonia_Argentina
Merriam-Webster. "Proximal":
https://www.merriam-webster.com/dictionary/proximal
Lexico. "Proximal":
https://www.lexico.com/en/definition/proximal

Sassani and Bivens (2017) (Pg. 7-8, 15, and 28):

https://www.researchgate.net/publication/332553212_The_Chinese_colossus_an_evaluation_of_the_phylogeny_of_Ruyangosaurus_giganteus_and_its_implications_for_titanosaur_evolution

Link 2:
https://peerj.com/preprints/2988v1.pdf

Mannion and Calvo (2011) ("Additional Remains Referred To Andesaurus" p. 3):

https://academic.oup.com/zoolinnean/article/163/1/155/2625609

Sizes of Other Sauropods:
https://psdinosaurs.blogspot.com/2018/12/size-calculations-for-herbivorous.html
Time of Candeleros and Huincul Formations:
https://psdinosaurs.blogspot.com/2020/07/were-giganotosaurus-and-mapusaurus-same_24.html
Sellers et al., (2013):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864407/

Monday, July 27, 2020

Dino Bios: Alamosaurus.

Alamosaurus:

Time: Campanian-Maastrichtian of the late Cretaceous period: 84-66 million years ago.
Place: North America.
Length: 67-223 feet (20.4-67.9 meters).
Diet: Herbivore.

Let's talk about Alamosaurus, one of the largest animals that ever lived!

Description:
Alamosaurus lived 84-66 million years ago in North America, during the Campanian-Maastrichtian of the late Cretaceous period (Woodward, 2005, Chapter 2 Part 2: "Tectonic Setting" pg. 6) (Rivera-Sylva et al., 2006, pg. 66 "Geologic and Stratigraphic Setting") (Lehman et al., 2006, "Abstract") (Longrich et al., 2010, "Abstract," pg. 276) (Fowler and Sullivan, 2011, pg. 686 "Geological setting") (Wick et al., 2015, "Abstract") (Carrano and D'Emic, 2015, p. 2) (Tykoski and Fiorillo, 2016, "Geological setting"). It was

67-223 feet long (20.4-67.9 meters), and was the largest dinosaur in its environment. Alamosaurus had osteoderms on its body, which is similar to saltasaurids (Carrano and D'Emic, 2015, pg. 3).

Sauropod dinosaurs had rhamphotheca, or a beak-like structure made of keratin. This beak would have protected the sauropod's teeth and kept them in place, since fossilized sauropod teeth are usually found in good condition and connected to their skulls (John Pickrell, 10/10/19) (Pickrell, 10/17/19). Interestingly, dinosaurs couldn't move their tongues (Mindy Weisberger, 2018) (ScienceDaily, 2018).

Alamosaurus Skeleton Reconstruction (EurekAlert!, 2016):

Friends:
Alamosaurus coexisted with Triceratops (20-30 feet; 6.2-9.2 meters), Ankylosaurus (18-20 feet; 5.5-6.1 meters), Denversaurus (18 feet; 5.5 meters), Edmontosaurus (24-51 feet; 7.4-15.6 meters), Pachycephalosaurus (10 feet; 3.0 meters), and Struthiomimus (16 feet; 4.9 meters).

Enemies:
Alamosaurus' predators consisted mainly of T. rex, but the tyrannosauroid Dryptosaurus
(24 feet; 7.3 meters) would've been a threat to the younger individuals. Another predator included the dromaeosaur Dakotaraptor (13-17 feet; 3.8-5.2 meters). Another enemy (maybe for the young mainly) was the azhdarchid pterasaur Quetzalcoatlus (52 feet; 15.7 meters).

Alamosaurus vs. T. rex from Black (2009):