Welcome Guest [Log In] [Register]
Welcome to Carnivora. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Username:   Password:
Add Reply
  • Pages:
  • 1
  • 10
Spinosaurus aegyptiacus
Topic Started: Jan 7 2012, 12:44 AM (59,633 Views)
Wolf Eagle
Member Avatar
M E G A P H Y S E T E R
[ *  *  *  *  *  * ]
Spinosaurus aegypticus

Posted Image

Spinosaurus (meaning "spine lizard") is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. This genus was first known from Egyptian remains discovered in 1912 and described by German paleontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in recent years. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species S. maroccanus has been recovered from Morocco. Spinosaurus may be the largest of all known carnivorous dinosaurs, even larger than Tyrannosaurus and Giganotosaurus. Estimates published in 2005 and 2007 suggest that it was 12.6 to 18 metres (41 to 59 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. The skull of Spinosaurus was long and narrow like that of a modern crocodilian. Spinosaurus is thought to have eaten fish; evidence suggests that it lived both on land and in water like a modern crocodilian. The distinctive spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display.

Posted Image

Skull

The skull had a narrow snout filled with straight conical teeth that lacked serrations. There were six or seven teeth on each side of the very front of the upper jaw, in the premaxillae, and another twelve in both maxillae behind them. The second and third teeth on each side were noticeably larger than the rest of the teeth in the premaxilla, creating a space between them and the large teeth in the anterior maxilla; large teeth in the lower jaw faced this space. The very tip of the snout holding those few large anterior teeth was expanded, and a small crest was present in front of the eyes. Using the dimensions of three specimens known as MSNM V4047, UCPC-2, and BSP 1912 VIII 19, and assuming that the postorbital part of the skull of MSNM V4047 had a shape similar to the postorbital part of the skull of Irritator, Dal Sasso et al. (2005) estimated that the skull of Spinosaurus was 1.75 meters (5.7 ft) long. The Dal Sasso et al. skull length estimate was questioned because skull shapes can vary across spinosaurid species.

Posted Image

Posted Image

Size

Since its discovery, Spinosaurus has been a contender for the longest and largest theropod dinosaur. Both Friedrich von Huene in 1926 and Donald F. Glut in 1982 listed it as among the most massive theropods in their surveys, at 15 meters (49 ft) in length and upwards of 6 tons in weight. In 1988, Gregory Paul also listed it as the longest theropod at 15 meters (49 ft), but gave a lower mass estimate of 4 tonnes (4.4 short tons).
Dal Sasso et al. (2005) assumed that Spinosaurus and Suchomimus had the same body proportions in relation to their skull lengths, and thereby calculated that Spinosaurus was 16 to 18 meters (52 to 59 ft) in length and 7 to 9 tonnes (7.7 to 9.9 short tons) in weight. The Dal Sasso et al. estimates were criticized because the skull length estimate was uncertain, and (assuming that body mass increases as the cube of body length) scaling Suchomimus which was 11 meters (36 ft) long and 3.8 tonnes (4.2 short tons) in mass to the range of estimated lengths of Spinosaurus would produce an estimated body mass of 11.7 to 16.7 tonnes (12.9 to 18.4 short tons).

François Therrien and Donald Henderson, in a 2007 paper using scaling based on skull length, challenged previous estimates of the size of Spinosaurus, finding the length too great and the weight too small. Based on estimated skull lengths of 1.5 to 1.75 meters (4.9 to 5.7 ft), their estimates include a body length of 12.6 to 14.3 meters (41 to 47 ft) and a body mass of 12 to 20.9 tonnes (13 to 23.0 short tons). The lower estimates for Spinosaurus would imply that the animal was shorter and lighter than Carcharodontosaurus and Giganotosaurus. The Therrien and Henderson study has been criticized for the choice of theropods used for comparison (e.g., most of the theropods used to set the initial equations were tyrannosaurids and carnosaurs, which have a different build than spinosaurids), and for the assumption that the Spinosaurus skull could be as little as 1.5 meters (4.9 ft) in length. Improvement of the precision of size estimates for Spinosaurus requires the discovery of more complete remains as available for some other dinosaurs, especially the limb bones of Spinosaurus which are "hitherto unknown."

Posted Image

Posted Image

Diet

It is unclear whether Spinosaurus was primarily a terrestrial predator or a piscivore, as indicated by its elongated jaws, conical teeth and raised nostrils. The hypothesis of spinosaurs as specialized fish eaters has been suggested before by A. J. Charig and A. C. Milner for Baryonyx. They base this on the anatomical similarity with crocodilians and the presence of digestive acid-etched fish scales in the rib cage of the type specimen. Large fish are known from the faunas containing other spinosaurids, including the Mawsonia, in the mid-Cretaceous of northern Africa and Brazil. The only direct evidence for spinosaur diet comes from related European and South American taxa. Baryonyx was found with fish scales and bones from juvenile Iguanodon in its stomach, while a tooth embedded in a South American pterosaur bone suggests that spinosaurs occasionally preyed on pterosaurs. Spinosaurus was likely to have been a generalized and opportunistic predator, possibly a Cretaceous equivalent of large grizzly bears, being biased toward fishing, though it undoubtedly scavenged and took many kinds of small or medium-sized prey.

In 2009, Dal Sasso et al. reported the results of X-ray computed tomography of the MSNM V4047 snout. As the foramina on the outside all communicated with a space on the inside of the snout, the authors speculated that Spinosaurus had pressure receptors inside the space that allowed it to hold its snout at the surface of the water to detect swimming prey species without seeing them. A 2010 isotope analysis by Romain Amiot and colleagues found that oxygen isotope ratios of spinosaurid teeth, including teeth of Spinosaurus, indicate semiaquatic lifestyles. Isotope ratios from tooth enamel and from other parts of Spinosaurus (found in Morocco and Tunisia) and of other predators from the same area such as Carcharodontosaurus were compared with isotopic compositions from contemporaneous theropods, turtles, and crocodilians. The study found that Spinosaurus teeth from five of six sampled localities had oxygen isotope ratios closer to those of turtles and crocodilians when compared with other theropod teeth from the same localities. The authors postulated that Spinosaurus switched between terrestrial and aquatic habitats to compete for food with large crocodilians and other large theropods respectively.

Posted Image

Source: Wikipedia
Edited by Taipan, Jan 22 2012, 12:42 PM.
Offline Profile Quote Post Goto Top
 
Taipan
Member Avatar
Administrator

Spinosaurus aegyptiacus

Posted Image

Spinosaurus (meaning "spine lizard") was a genus of theropod dinosaur that lived in what is now North Africa, from the Albian to early Cenomanian stages of the Cretaceous Period, about 95 to 93 million years ago. It is unclear whether there are one or two species. The best known is S. aegyptiacus from Egypt, though a second species (S. marocannus) has been recovered from Morocco.

The distinctive "spines" of Spinosaurus, which were long extensions of the vertebrae, grew up to 2 metres (6.6 feet) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that they were covered in muscle and formed a hump or ridge. Multiple functions have been put forward for this structure, including thermoregulation and display. According to a study by paleontologist Cristiano Dal Sasso of the Civic Natural History Museum in Milan and his colleagues in 2006, it is the largest of all carnivorous dinosaurs, even larger than Tyrannosaurus rex and Giganotosaurus. If the estimates are correct, Spinosaurus would be the longest theropod, measuring 16 - 18 m long (52.5 - 59.1 ft), around 6 m tall (20 ft), and reached weights up to 9 tons.

Anatomy

Spinosaurus is called "spiny lizard" because it had a series of large neural spines up to 6 feet (1.8 m) long coming out of its back vertebrae, probably forming a sail-like fin that may have helped in thermoregulation, mating rituals and/or intraspecies rivalry. Spinosaurus had a relatively flexible upper spine (these vertebrae had modified ball-and-socket-joints) so it could arch its back somewhat, perhaps being able to spread the sail (like opening the ribs of a fan).

Spinosaurus was bipedal (it walked on two legs). It was about 40-50 feet long (12-15 m) and weighed 6 tons or more (some paleontologists estimate it weighed up to perhaps 12 tons); it is the largest known spinosaurid (a type of large, meat-eating dinosaur). It had a large head with sharp, straight, non-serrated teeth in powerful, crocodile-like jaws. Its arms were smaller than its legs but were larger than the arms of most other theropods. It may have gone on all fours at times.

When Spinsaurus lived

Spinosaurus lived during the middle Cretaceous period, about 95 million years ago in the tropics near sea level. At the same time and place, there was another sail-backed dinosaur, Ouranosaurus, a large, bipedal plant-eater.

Diet & Teeth

Posted Image
Spinosaurus was a carnivore, a meat eater with huge teeth and powerful jaws. It ate dinosaurs and large fish. The teeth were long and sharp but had little or no serrations. It was a large, fierce predator that could perhaps even kill large sauropods. Spinosaurus may also have been a scavenger.

  • Weight; Varied from 6 tons to 9 tons
  • Size; 40-55 feet (12-17 m) long
  • Diet; Carnivore (meat-eater). Spinosaurus probably ate plant-eating dinosaurs and large fish.
Posted Image

Posted Image
Offline Profile Quote Post Goto Top
 
Taipan
Member Avatar
Administrator

TheROC
 
Recent spinosaurid article translated (roughly) from Italian.

http://theropoda.blogspot.com/2009/01/spinosaurid-paleobiology-more-than-just.html

Quote:
 
23 gennaio 2009 23 January 2009
Spinosaurid paleobiology, more than just “croc-mimic” Spinosaurid paleobiology, more than just "croc-mimic"

Posted Image

Why are so spinosauri "bizarre"? There is no doubt that their peculiarities compared to other theropodi indicating a specific environment, different from those of other forms. The fact that spinosauri are often portraits as part of the crocodiles is a sufficient and comprehensive comparison? This post aims to explore the ecology of spinosauri, not just the usual question of the elongated snout and conical teeth (important details but not the only ones to see these animals).

I do not deny that there are obvious similarities between some spinosauridi and crocodiles, particularly nell'allungamento of the rostrum, in the form "a rosette spatolato" premascellare of the area, in the form of teeth (tapered, slightly curved, with serration vestigiale if not absent). These characters suggest a reduced ability lacerating teeth, replaced by a better ability to pierce and "impaling" prey size medium to small. Although the first interpretation of the craniofacial anatomy and the dental piscivoria, it is noted that the spinosauridi should not be solely piscivori, as indicated by the remains of ornithopode average size of the stomach contents Baryonyx (Charig & Milner, 1997) and the tooth spinosaurino sticking in a series of cervical pterosauro (see related post).

How does the jaw of a spinosauride? Recent findings from Morocco (explained in SVPCA 2008) show that the square (the bone of the skull that articulates the mandible) of spinosauri had conformed to the expansion in width of mouth. This adjustment allowed the ingestion of relatively large prey, like fish and vertebrate small-medium size, almost without the assistance of chewing. In previous post I argued that the morphology of the posterior region of the skull spinosauride be better understood by reconstructing a posture of the head, not horizontal, but rostroventrale with the opening facing jug partially down.If you look at the picture below, you will see that swinging the skull with such a posture, we have the main axis of the maxillary teeth, the axis of the lacrimal and dell'Orbo that have vertically (blue lines), as in most theropodi. An interesting consequence of this morphology is that the act of closing the mouth automatically pushes the prey to their teeth and jaw, at the same time, towards the inside of the mouth (green arrow). This posture also has the honor of unlocking the visual field of spinosauro dall'ingombro given by its rostrum, stereoscopy any better (but this can only determine this with skulls and articulated deformable).

Posted Image

The result is a bite "Impaler" that pushes the prey directly into the conical teeth, where it is literally pierced. Moreover, the fact that the main jaw tooth, the one who first impact with the prey, is parallel to the lines of muscle strength is a clear adaptation to maximize the effectiveness of the bite.
How powerful was that fish? A precise quantification is not possible, however, it should be noted that with increasing length of the rostrum, increases the moment of force exerted by the muscles at the mandibular rostrum. The skull of a long spinosauro was adapted to withstand the forces exerted by the same bite? The cross section of the rostrum, triangular, the presence of the long dorsal nasal crest that served as a point of discharge of the forces and the presence of long secondary palate (a mechanical contrivance to resist twisting), all adjustments are designed to support the intense stress caused from powerful bites. A further indication of this capacity is, at least in Spinosaurus, the rearward position of the nostrils: this meant that the entire region prior to the post nostrils were formed only by compact bone, with no holes or soft part, and then allowed to exercise its level of the rostrum of the considerable pressures without the risk of damaging vital parts such as the nostril. A demonstration of the incredible strength of the rostrums spinosauro is the tafonomia: the rostrums of spinosauro, as the example of Milan, it is often found still articulated after a hundred million years, while much of the skeleton is lost.

The move spinosauri as their bizarre skull? The anatomy of occipital Irritator (Sues et al., 2002) is very instructive: unlike allosauroidi in this condition, in which the muscle processes are specialized to enhance the ability to lower his head and shake sideways (adaptation brontof*gico "to tear the deep side of a prey size medium-large: red areas in the skull of Allosaurus below), are absent in spinosauri muscle listings specifically adapted to increase the lateral motion of the head, or push powerfully downwards (as basal tubers, which are important include the ventral muscles of the neck).

Posted Image

Then, the skull shows no adaptations to violently shake the prey, which was probably killed by the bite and teeth. The skull and jaw muscles and suggests that spinosauri have evolved a mechanism of "impaling" of medium-sized prey, seized with a relatively quick bite and powerful, deeply pierced with the rostral teeth and swallowed almost whole.
The anatomy dell'arto earlier Baryonyx known and probable spinosauroide Megaraptor, is in line with this hypothesis: as I wrote recently, Megaraptor shows that the earlier adjustments dell'arto suggest a technique based on hunting "impaling" of prey to operates the huge first unguale falciforme hand, moved by powerful pectoral muscles. Therefore, it is likely that the spinosauri they were "opportunistic Impaler", theropodi specialized for catching medium-sized prey (fish and terrestrial vertebrates), which were seized by mouth and pierced the concerted action of the teeth and the hypertrophic dell'unguale hand.Obviously, given the amount of Spinosaurus, it is possible that in his case they were also prey of medium size, as ornithopodi or young sauropodi.





Some things to take away from this:

-From the diagram of Spinosaurus skull, it is apparent that their bite is clear adapted for maximum effect for its morphology, with the largest tooth being parallel to the jaw muscles.

-Spinosaurus had a lot of adaptations for withstanding the stresses of powerful bites despite its elongated skull. Such as the cross section of its rostrum, the nasal crest as a point of discharge of the forces, and most particularly the presence of a strong secondary palate (crocodilians have this as well) which is an adaptation partly for resisting torsion that comes from biting into prey and the subsequent struggle that comes with it.

-Also the fact that its nostrils are placed so far back means before that point, the skull is entirely made of compact solid bone. Another adaption for strength.

-It also suggests the relatively decent shape that spinosaurus snouts are found in to be an indicator of the great strength of the skull. Which as I see it, is a fair point to make as the skulls of spino's contemporary, carcharodontosaurus, have often been found in much worse, much more fragmented shape than spino's. That goes for any theropod pretty much.

(As an aside spinosaurus needed a strong skull partly because the fish it was preying on were quite heavily armored compared to today, insofar that there scales were made up of solid enamel. Which is harder than bone, and the scales grow as the fish does. The extensive secondary palate and the farther placed nostrils and the generally greatly reduced holes in the skull are adaptations that other theropods such as the allosaur relatives like carcharodontosaurus don't have. And thus their skulls despite being wider than spinosaurus' aren't as solid. Spino's relatives such as suchomimus and baryonyx don't have a very extensive secondary palate themselves, and their nostrils are placed much further up front like in typical theropods, thus their skulls are nowhere near as adapted for strength as spinosaurus' )

-The article also compares an occipital (rearward) view of allosaurus' skull vs irritator's skull (irritator is a much much smaller cousin of spinosaurus). It says Allosaurus had muscle adaptations that allowed it to laterally shake its head while biting prey, which seems to be absent in at least irritator.

-It says Megaraptor is possibly another spinosaurid and spinosaurids probably hunted both with their mouth for grabbing/piercing in concertation with their enlarged forelimbs equipped with huge talons. Spinosaurus due their large population possibly also hunted ornithopods ( iguanodonts and hadrosaurs fit in this) and young sauropods, both of which would be multi-ton prey. (The mouth grab/pierce and hand talons stabbing combo would be very beneficial here I imagine)

Overall this is a good start, but there are still some important quantifiable data for spino that we need such as just how much, stress it can handle, as well as potential biteforce of course. All that should be coming down the pipe soon. Or at least hopefully sooner, rather than later.

Oh and here are some supplementary images from this link:
http://spinosauridae.fr.gd/

Firstly here is an occipital view of spinosaurus' skull. Compared to the irritator and even allosaurus skull image, I'd say it looks much more impressive.
Posted Image

And I'm sure you'll love this, an idea of how big spinosaurus' skull was.
Posted Image
(the original image shows the guy holding a section of spino's snout, up to the nostril)

For comparison's sake, here's Paul Sereno and a Carcharodontosaurus skull.
Posted Image

And here he is next to a Sarchosuchus skull.
Posted Image
Offline Profile Quote Post Goto Top
 
Taipan
Member Avatar
Administrator

TheROC
 
Posted Image

A Spinosaurus exhibit at the "Dinosaur Expo 2009 - The Miracle of Deserts" in Chiba, Japan.

The skull size represented here seems a very conservative, looks only about 5 feet (which about the same as Suchomimus', a much smaller cousin.) But that is a solidly built skull nonetheless.


Compare how much it differs from a suchomimus skull of similar length:
Posted Image

Offline Profile Quote Post Goto Top
 
Taipan
Member Avatar
Administrator

TheROC
 
Posted Image

a scale i made.
Offline Profile Quote Post Goto Top
 
Taipan
Member Avatar
Administrator

Big Al
 
TOTAL BIG NEWS

They found the LOWER LIMB(S) of Spinosaurus aegyptiacus, and they are much shorter than expected, DESPITE THE FACT that S. aegyptiacus was the least semiaquatic spinosaurid. A guy working with Horner told me that. Why do i trust him? Because he works with Maganuco too :P!

From left to right
Anonymous person, Simone Maganuco, Andrea Cau and Cristiano Dal Sasso
https://lh3.googleusercontent.com/-7tPXmXqItD0/TXx5zSFpDjI/AAAAAAAADLc/QNK2lNdIlPs/4perspino.jpg

Also, here more pics of the WONDERFUL reconstruction Dal Sasso and Maganuco made
https://lh4.googleusercontent.com/-oYhQwbOs8Ko/TXQI3n8Jc1I/AAAAAAAAANg/090o2SVpqDI/spino%2521.jpg
http://parma.repubblica.it/images/2011/04/01/092632751-6ec9a119-a0f1-4d38-9906-63d2267c3358.jpg
http://3.bp.blogspot.com/-ewibs2_LWiE/TX6GF3CXBZI/AAAAAAAAAvw/PoRPFRPO578/s1600/DSC01587.JPG
http://www.geomodel.it/images/Spinosaurus-aegyptiacus/spinosaurus-13.jpg
Offline Profile Quote Post Goto Top
 
Megafelis Fatalis
Carnivore
[ *  *  *  *  *  *  * ]
by ~ Shartman
Posted Image

I got access to better scaling and photographiv documentation of the Spinosaurus type specimen, so along with Jaimie Headden's observation [link] that one of the presumed sacrals was actually an anterior caudal, I set out to revisit Spinosaurus.

Of course much is still unknown, but with the help of Irritator (including Angaturama) and related animals like Baryonyx and Suchomimus I feel like the general proportions are probably about correct, although there is room for uncertainty in the pectoral girdle, forelimbs, and (to a lesser extent) hindlimbs.
Edited by Megafelis Fatalis, Jan 22 2012, 02:04 AM.
Offline Profile Quote Post Goto Top
 
Megafelis Fatalis
Carnivore
[ *  *  *  *  *  *  * ]
http://qilong.wordpress.com/2010/05/16/weekly-picture-3-spinosaurus-spines/
Offline Profile Quote Post Goto Top
 
Mack
Member Avatar
Heterotrophic Organism
[ *  *  * ]
A documentary from Mega-Beasts (Monster Resurrected) named Biggest killier Dino about Spinosaurus



Offline Profile Quote Post Goto Top
 
DinosaurMichael
Member Avatar
Apex Predator
[ *  *  *  *  *  *  *  * ]
So I heard Spinosaurus has a really strong bite force. Does anyone know how strong it was? I guess maybe between 2-3 tons I assume.
Offline Profile Quote Post Goto Top
 
Megafelis Fatalis
Carnivore
[ *  *  *  *  *  *  * ]
Miyess
Posted Image
Edited by Taipan, Jan 22 2012, 12:38 PM.
Offline Profile Quote Post Goto Top
 
genao87
Heterotrophic Organism
[ *  *  * ]
DinosaurMichael
Jan 20 2012, 12:26 PM
So I heard Spinosaurus has a really strong bite force. Does anyone know how strong it was? I guess maybe between 2-3 tons I assume.
Spino's bite force is estimated to be roughly 3 tons. There is very little data on it but seeing how big he was and also that he ate fish and his jaws were researched to be strong, it is believe that the 3 ton estimate is a good result.


This makes Spino's bite force second only to T. Rex. T. Rex had some different results, some say it is 3 tons, 4 tons, or 3 to 6 tons. I heard even higher like 11 or 14 tons but there is not much data backing that up.
Offline Profile Quote Post Goto Top
 
SameerPrehistorica
Heterotrophic Organism
[ *  *  * ]
The guy who is holding the spinosaurus skull which is an art...That doesn't seem to be 8 foot skull. I mean..when i first read about Spinosaurus being the largest carnivore, i noted that it had a estimated 8 foot skull.So i thought the Spinosaurus had 8 foot skull.But in these size estimates pictures, it seems like it is 6 feet only.So what is that 8 foot skull all about ?
Edited by SameerPrehistorica, Jan 26 2012, 03:33 PM.
Offline Profile Quote Post Goto Top
 
DinosaurMichael
Member Avatar
Apex Predator
[ *  *  *  *  *  *  *  * ]
genao87
Jan 24 2012, 05:32 PM
DinosaurMichael
Jan 20 2012, 12:26 PM
So I heard Spinosaurus has a really strong bite force. Does anyone know how strong it was? I guess maybe between 2-3 tons I assume.
Spino's bite force is estimated to be roughly 3 tons. There is very little data on it but seeing how big he was and also that he ate fish and his jaws were researched to be strong, it is believe that the 3 ton estimate is a good result.


This makes Spino's bite force second only to T. Rex. T. Rex had some different results, some say it is 3 tons, 4 tons, or 3 to 6 tons. I heard even higher like 11 or 14 tons but there is not much data backing that up.
Okay thanks.
Offline Profile Quote Post Goto Top
 
SpinoInWonderland
The madness has come back...
[ *  *  *  *  *  *  *  * ]
Posted Image
Posted Image
Posted Image
Posted Image
Posted Image
Edited by SpinoInWonderland, Sep 13 2012, 12:59 AM.
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
ZetaBoards - Free Forum Hosting
Free Forums with no limits on posts or members.
Learn More · Sign-up for Free
Go to Next Page
« Previous Topic · Dinosauria Species profiles · Next Topic »
Add Reply
  • Pages:
  • 1
  • 10

Find this theme on Forum2Forum.net & ZNR exclusively.