Tuesday, March 13, 2018

Dino Bios: Allosaurus.

Allosaurus:
Allosaurus: from Walking With Dinosaurs:
Time: 157-145 million years ago, Kimmeridgian-Tithonian of the late Jurassic period.
Place: North America, Europe, and (?)Africa.
Size: 26-52 feet (7.9-15.8 meters).
Weight: 2.3-3 tons (Foth et al., 2011). (Maybe more)
Diet: Carnivore.

Let's talk about my favorite Jurassic carnivore, Allosaurus!

Description:
Allosaurus is the largest carnivorous theropod of late-Jurassic North America. It was 26-52 feet (7.9-15.8 meters), and there are currently six different species of it that roamed North America, Africa, and Europe from the Kimmeridgian-Tithonian. It had two crests on the top of its skull, long arms, and hands with huge claws used for tearing flesh. It's neck muscles "allowed it to whip its head back and forward while attacking its prey" (Burns, 2013, p. 1).

According to Kenneth Carpenter (2002), in most predatory theropods used their mouths first to grab prey first, and then they would grab their prey "in a 'bear hug'" with their hands (pg. 72, "Conclusion"). For Allosaurus, its arms were relatively long and robust. The range of motion in its arms seems to have allowed it to grab and pull "moderately large prey" towards it. Carpenter says that evidence of Allosaurus using its arms to hunt large sauropods isn't present ("Biomechanical Analysis," pg. 71). If it didn't use its hands to hunt sauropods, then perhaps it used its jaws (Burns, 2013, p. 1). Text-figure 9 in Carpenter (2002) shows Allosaurus', and other theropod's, range of motion for their hands (pg. 69). Apparently, it can bend its hand quite well outward.

As for speed, Dececchi et al., (2020) says that theropods over 1000 kg would not be able to run fast, despite their different limb lengths. Instead, they were speed-walkers (Dececchi et al., 2020, "Abstract;" "Discussion," "Getting up to speed" p. 3; "Why tyrannosaurids?" p. 2) (EurekAlert, 2020). They could do this for a long time (The Canadian Press, 2020). The young seem to have been faster ("Results," "Relative leg length" p. 1), and pack-hunting was also suggested to help large theropods take down prey (The Canadian Press, 2020) (Dececchi et al., 2020, "Discussion," "Why tyrannosaurids?" p. 2-3).

A lot of specimens have been called different genera, but now they are all considered to be Allosaurus. This includes Epanterias, Creosaurus, Labrosaurus, Camptonotus, Wyomingraptor, Madsenius, and Antrodemus (Weishampel et al., 2004, pg. 74-75) (Galton et al., 2015) (Mortimer, The Theropod Database Blog, 2015, "Madsenus and Wyomingraptor") (Madsen, 1976/1993, pg. 12-13) (Gilmore, 1920) (Osborn, 1916, pg. 28 figure 27).

Allosaurus' reached its maximum size at age 15 (Bybee et al., 2006, "Abstract") (Joseph Castro, 2016 p. 8), and sexual maturity at around 10 years of age (Lee and Werning, 2008, "Abstract" and "Results, RM Estimated and Skeletochronology").  

Carnivorous theropod dinosaurs had enamel in their teeth, so they must have had lips to cover and protect their teeth (Reisz and Larson, 2016, pg. 64-66) (Blake Eligh, 2016) (Mindy Weisberger, 2016) (Emanuela Grinberg, 2016) (Phys, 2016). Therefore, Allosaurus would have had lips covering its teeth. Interestingly, dinosaurs couldn't move its tongues (Mindy Weisberger, 2018) (ScienceDaily, 2018).

Evers et al., (2020) reconstructed what Allosaurus' skull would have looked liked when it was reconstructed properly. It is similar to the specimen AMNH 600's, which was considered to be "Creosaurus."

Allosaurus Specimen MOR 693's ("Big Al") Skull (Evers et al., 2020, Figure 6):
AMNH 600's Skull (Paleofile) (Osborn, 1903, pg. 698):
It seems that AMNH 600's skull was the accurate Allosaurus skull.

Times and Places:
Allosaurus was discovered in North America and Europe, with a possibility of it being in Africa as well. In North America, Allosaurus fossils come from the Morrison Formation of the late/upper Jurassic period. The Morrison Formation is made up of three major members: Tidwell, Salt Wash, and Brushy Basin (Kowallis et al., 1998, "Abstract") (Scott et al., 2001, pg. 12-14) (The University of Utah, "Morrison Formation"). According to Kowallis et al., (1998), the Tidwell Member is 155 million years old. The Brushy Basin Member is 150-148 million years old. Thus, the Morrison Formation is Kimmeridgian-Tithonian in age ("Abstract"). The Salt Wash Member is located in between the Tidwell and Brushy Basin Members (Chure and Loewen, 2020, "Age"), so it must be around 155-150 million years old. However, the Brushy Basin's maximum age seems to be 153-145 million years old (Kowallis et al., 1991, "Abstract") (Irmis et al., 2013, pg. 282). Therefore, the Salt Wash Member seems to be 155-153 million years old. In total, the Tidwell Member is 157-155 million years old, the Salt Wash Member is 155-153 million years old, and the Brushy Basin Member is 153-145 million years old. In total, the Morrison Formation is Kimmeridgian-Tithonian in age, ranging from 157-145 million years ago. Palynomorphs and calcareous microfossils prove this as well (Turner and Peterson, 1999, pg. 89-90) (Marjanovic and Laurin, 2014, pg. 2) (Dinosaur National Monument, "Rhadinosteus parvus"). Therefore, Allosaurus lived from 157-145 million years ago in North America (Dinosaur National Monument, "The Dinosaurs of Dinosaur").

In Europe, Allosaurus remains come from the Lourinha Formation. The timing of the Lourinha Formation seems to be Kimmeridgian-Tithonian in age (Mateus et al., 2006, pg. 5) (Octavio Mateus, 2006, pg. 2) (Russo et al., 2017, pg. 4) (Mateus et al., 2017, "Lithostratigraphic framework," pg. 80). Therefore, it seems to be the same age as the Morrison Formation (Octavio Mateus, 2006, pg. 2).

In Africa, possible Allosaurus remains come from the Tendaguru Formation. The Tendaguru Formation is Kimmeridgian-Tithonian (Octavio Mateus, 2006, pg. 2) (Kristian Remes, 2006, "Abstract") (Sattler and Schwarz, 2015, "Material"). (?)Allosaurus remains come from the Lower Dinosaur and Middle Dinosaur Members of the Tendaguru Formation, which are both Kimmeridgian in age (Bussert et al., 2009, "Members of the Tendaguru Formation," "Lower Dinosaur Member" and "Middle Dinosaur Member," pg. 156-157, 160-162). However, the Allosaurus fossil discovered there, called Allosaurus tendagurensis, is considered a nomen dubium (questionable) (Oliver M. W. Rauhut, 2011, pg. 209).

In summary, Allosaurus lived during the Kimmeridgian-Tithonian of late-Jurassic North America and Europe. It might have also lived in Africa, but it's not for certain.

Sizes and Species:
The amount of species that pertain to Allosaurus are numerous. So far, I've been able to find seven. However, according to Evers et al., (2020), there doesn't seem to be any diagnostic features between the multiple species of Allosaurus, based on a study of multiple skulls (mainly cheek or jugal bones) ("Introduction," Figure 5, "Discussion," and "Conclusion"). Therefore, it seems that Allosaurus fragilis is the only valid species of Allosaurus so far. All specimens listed below belong to Allosaurus fragilis until further notice.

1. USNM 4734:
Length: 26 feet (7.9 meters).

 USNM 4734's Skull (Paleofile):
2. MOR 693 ("Big Al"):
Length: 35 feet (10.6 meters).
Age: Subadult.
Adult Length: 39 feet (12.0 meters).

 MOR 693 ("Big Al"):
3. OMNH 01935:
Length: 43 feet (13.0 meters).

 OMNH 01935's Humerus (Left) (Cuesta et al., 2018): 
4. AMNH 5767:
Length: 52 feet (15.8 meters).

AMNH 5767 (from Paleofile):
Prey:
Allosaurus' prey consisted of sauropods, ornithopods, and stegosaurs. In North America for example, Allosaurus hunted the sauropods Barosaurus, Brachiosaurus and Camarasaurus, Maraapunisaurus, and other herbivores like Camptosaurus, Stegosaurus, and Mymoorapelta. In Africa, it hunted the stegosaur Kentrosaurus and the sauropod Giraffatitan.

Allosaurus vs. Stegosaurus from Walking With Dinosaurs Ep. 2-Time of the Titans:
Enemies:
Allosaurus' enemies were numerous. In North America, it consisted of Ceratosaurus, Torvosaurus, Stokesosaurus, and Saurophaganax. In (?)Africa, it consisted of (?)Ceratosaurus and Veterupristisaurus. In Europe, it consisted of Ceratosaurus, Torvosaurus, and Lusovenator.

 Links:
Times and Places:
Morrison Formation:
Kowallis et al., (1991) ("Abstract"):
https://www.sciencedirect.com/science/article/pii/019566719190003U
Full:
http://geology.byu.edu/Home/sites/default/files/kowallis_agebrushybasin_91.pdf
Kowallis et al., (1998) ("Abstract"):
http://geology.byu.edu/home/sites/default/files/kowallis_morrison_age_98.pdf
Turner and Peterson (1999) ("Age," pg. 89-90):
https://books.google.com/books?hl=en&lr=&id=qeRM16ndBx4C&oi=fnd&pg=PA77&ots=W5Kj88zd2x&sig=CZ76lISv4Bbi3BXBoWcGMHGg124#v=onepage&q&f=false
Scott et al., (2001) (Pg. 12-14):
https://pubs.usgs.gov/imap/i-2740/i-2740pm.pdf
Irmis et al., (2013) (Pg. 282):
https://www.researchgate.net/publication/260632793_Early_Crocodylomorpha
Marjanovic and Laurin (2014) (Pg. 2):
https://www.researchgate.net/publication/260075695_69_Marja_Laurin_App_comp
Chure and Loewen (2020) ("Age"):
https://peerj.com/articles/7803/
The University of Utah ("Morrison Formation"):
https://sed.utah.edu/Morrison.htm
Dinosaur National Monument ("Rhadinosteus parvus"):
https://www.nps.gov/dino/learn/nature/rhadinosteus-parvus.htm
Dinosaur National Monument ("The Dinosaurs of Dinosaur"):
https://www.nps.gov/dino/learn/nature/dinosaurs-of-dinosaur.htm
Lourinha Formation:
Russo et al., (2017) (Pg. 4):
Mateus et al., (2006) (pg. 5):
https://docentes.fct.unl.pt/sites/default/files/omateus/files/mateus_walen_antunes_-_2006_-_the_large_theropod_fauna_of_the_lourinha_formation__portugal__and_its_similarity_to_the_morrison_formation__with_a_description_of_a_new_species_of_allosaurus.pdf
Octavio Mateus (2006) (Pg. 2):
https://www.researchgate.net/publication/40662981_Late_Jurassic_dinosaurs_from_the_Morrison_formation_USA_the_Lourinha_and_Alcobaca_Formations_Portugal_and_the_Tendaguru_Beds_Tanzania_a_comparison
Tendaguru Formation:
Sattler and Schwarz (2015) ("Material"):
Oliver M. W. Rauhut (2011) (Pg. 199-202; 202-205)
https://www.academia.edu/25456862/Theropod_dinosaurs_from_the_Late_Jurassic_of_Tendaguru_Tanzania
Bussert et al., (2009) ("Members of the Tendaguru Formation," "Lower Dinosaur Member" and "Middle Dinosaur Member," pg. 156-157, 160-162):
https://www.researchgate.net/publication/307714593_The_Tendaguru_Formation_Late_Jurassic_to_Early_Cretaceous_southern_Tanzania_definition_palaeoenvironments_and_sequence_stratigraphy
Kristian Remes (2006) ("Abstract"):
International Chronostratigraphic Chart (2020):
International Commission of Stratigraphy Website:
Specimens and Size:
https://psdinosaurs.blogspot.com/2020/07/size-calculations-for-allosaurus.html
Link 2:
Link 3:
https://psdinosaurs.blogspot.com/2018/01/carnivorous-theropod-sizes.html
Verified:
Othniel Charles Marsh (1877):
http://marsh.dinodb.com/marsh/Marsh%201877%20-%20Notice%20of%20new%20dinosaurian%20reptiles%20from%20the%20Jurassic%20formation.pdf
Evers et al., (2020) ("Introduction," Figure 5, "Discussion," and "Conclusion"):
https://peerj.com/articles/8493/
How Many Species of Allosaurus Are There!?:
https://psdinosaurs.blogspot.com/2020/02/how-many-species-of-allosaurus-are-there.html
Questionable Species:
Weishampel et al., (2004) (Pg. 74-75):

https://www.google.com/books/edition/The_Dinosauria/h4WRTHfTzXsC?q=baryonyx+tenerensis&gbpv=1&bsq=creosaurus#f=false
Mortimer. The Theropod Database Blog. "Madsenus and Wyomingraptor." 2015:

https://theropoddatabase.blogspot.com/2015/01/madsenius-and-wyomingraptor.html?m=1

Madsen (1976/1993) (Pg. 12-13):

Galton et al., (2015):
Oliver W. M. Rauhut (2011) (pg. 209):
Osborn (1916) (Pg. 28 figure 27):

http://digitallibrary.amnh.org/handle/2246/49

Weight:
Foth et al., (2011):
https://peerj.com/articles/940.pdf
Age:
Bybee et al., (2006):
Joseph Castro (2016):
Lee and Werning (2008) ("Abstract" and "Results," "RM Estimated and Skeletochronology"):
Lips:
Reisz and Larson (2016) (Pg. 64-66):
https://cansvp.files.wordpress.com/2013/08/csvp-2016-abstract-book-compressed.pdf
Blake Eligh (2016):
https://www.utoronto.ca/news/did-dinosaurs-have-lips-ask-university-toronto-paleontologist
Mindy Weisberger (2016):
https://www.livescience.com/54912-did-t-rex-have-lips.html
Emanuela Grinberg (2016):
https://www.cnn.com/2016/05/22/world/dinosaur-lips-teeth-study/index.html
Phys (2016):
https://phys.org/news/2016-06-dinosaurs-lips.html
Tongue:
Mindy Weisberger (2018):
https://www.scientificamerican.com/article/t-rex-couldnt-stick-out-its-tongue/
ScienceDaily (2018):
https://www.sciencedaily.com/releases/2018/06/180620150129.htm
Skull:
Evers et al., (2020) (Figure 6):
https://peerj.com/articles/8493/
How Many Species of Allosaurus Are There!?:
Jaw Strength:
Prey:
Enemies:
Dinosaur National Monument ("The Dinosaurs of Dinosaur"):
https://www.nps.gov/dino/learn/nature/dinosaurs-of-dinosaur.htm
Ceratosaurus:
Stokesosaurus:
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