Science

New Research Reignites Debate Around the Behavior of the Giant Dinosaur Spinosaurus

Spinosaurus Life Reconstruction

Life reconstruction of a Spinosaurus wading in the water and fishing. Credit: Image by Robert Nicholls

New research from Queen Mary University of London and the University of Maryland, has reignited the debate around the behavior of the giant dinosaur Spinosaurus.

Since its discovery in 1915, the biology and behavior of the enormous Spinosaurus has puzzled paleontologists worldwide. It was recently argued that the dinosaur was largely an aquatic predator, using its large tail to swim and actively pursue fish in the water.

The new study, published today in Palaeontologia Electronica, challenges this recent view of Spinosaurus suggesting that whilst it likely fed from the water, and may have swum, it wasn’t well adapted to the life of an aquatic pursuit predator. Instead it was like a giant (if flightless) heron or stork — snatching at fish from the shoreline while also taking any other small available prey on land or in water.

The researchers compared the features of Spinosaurus with the skulls and skeletons of other dinosaurs and various living and extinct reptiles that lived on land, in the water or did both. They found that whilst there were several pieces of evidence that contradicted the aquatic pursuit predator concept, none contradicted the wading heron-like model, and various lines of evidence actively supported it.

Reconstructed skeleton of a moderately sized Spinosaurus showing its famous sail-back and tail plume. Scale bar is 1 m. Credit: Image by Genya Masukawa

Dr. David Hone, Senior Lecturer at Queen Mary and lead author on the project said: “The biology and ecology of Spinosaurus has been troubling paleontologists for decades. Some recent studies have suggested that it was actively chasing fish in water but while they could swim, they would not have been fast or efficient enough to do this effectively. Our findings suggest that the wading idea is much better supported, even if it is slightly less exciting.”

Co-author Tom Holtz, Principal Lecturer in Vertebrae Paleontology, University of Maryland, said: “Spinosaurus was a bizarre animal even by dinosaur standards, and unlike anything alive today, so trying to understand its ecology will always be difficult. We sought to use what evidence we have to best approximate its way of life. And what we found did not match the attributes one would expect in an aquatic pursuit predator in the manner of an otter, sea lion, or short-necked plesiosaur.”

One of the key pieces of evidence unearthed by the researchers related to the dinosaur’s ability to swim. Spinosaurus was already shown to be a less efficient swimmer than a crocodile, but also has fewer tail muscles than a crocodile, and due to its size would have a lot more drag in the water.

Saddle-billed storks in Africa foraging with their beaks partly below water – Spinosaurus may have done something similar. Credit: Photograph by David Hone

Dr. Hone said: “Crocodiles are excellent in water compared to land animals, but are not that specialized for aquatic life and are not able to actively chase after fish. If Spinosaurus had fewer muscles on the tail, less efficiency and more drag then it’s hard to see how these dinosaurs could be chasing fish in a way that crocodiles cannot.”

Dr. Holtz added: “We certainly add that the evidence points to Spinosaurus feeding partly, even mostly, in the water, probably more so than any other large dinosaur. But that is a different claim than it being a rapid swimmer chasing after aquatic prey.” Though as Dr. Hone concludes: “Whilst our study provides us with a clearer picture of the ecology and behavior of Spinosaurus, there are still many outstanding questions and details to examine for future study and we must continue to review our ideas as we accumulate further evidence and data on these unique dinosaurs. This won’t be the last word on the biology of these amazing animals.”

Originally found in Egypt, Spinosaurus is thought to be one of the largest carnivorous dinosaurs to exist probably reaching over 15 m in length. The first known Spinosaurus fossils were destroyed by Allied bombing during World War II, which has hampered paleontologist’s attempts to understand these unusual creatures. More recently the dinosaur found fame in the 2001 film Jurassic Park III, where it battles and defeats a Tyrannosaurus rex.

Reference: “Evaluating the ecology of Spinosaurus: Shoreline generalist or aquatic pursuit specialist?” by David W.E. Hone and Thomas R. Holtz, Jr., January 2021, Palaeontologia Electronica.
DOI: 10.26879/1110

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  • Spinosauridae was the first mesoeucrocodylia so was not great fisher like the gator and it was not expected clearly it was aquatic nose point to sky not forward like land mesoeucrocodylia and it is on top of skull it’s nose is even more aquatic than modern crocodilian more whale like they know it is more land base than gator or Nile crocodile spinosaurus has fuse nasal it’s design to protect the skull from animal with legs fish do not have leg no web feet dwarf caiman has fuse nasal one of them like fossil gator type land mesoeucrocodylia and spinosaurus was design kill big animal it has death roll system jaw is design swallow big animal teeth was like Nile crocodile and t.rex. baryonyx is close together baryonyx allso has death roll system but it’s different it’s like early mesoeucrocodylia if only eat small animal why change allso change teeth even more to kill bigger animal allso have aquatic teeth .spinosaurus eyes elevation is not advance as modern crocodilian this clearly show baryonyx spinosaurus not as aquatic as them .spinosauridae has all classic feature of modern crocodilian lack neural arch so they can survive death roll roll over big sail hump neural spine and clearly no dinosaur can match weoponry of modern crocodilian the greatest dinosaur ever.modern crocrocodilian monster eusuchian centra joint is design catch those fast fish they are so violent fast without those joint backbone will break if was never good fisher those joint will never developed fuse nasal very land base feature clearly these feature do not match any modern crocodilian clearly closes won to it is dwarf caiman so probably simular to gator but more land base so that fuse nasal was developed because it was the first mesoeucrocodylia

  • They are saying YouTube video is Lieing crocodile hunt fish we know Nile crocodile in water open it’s mouth bipedal waiting for fish allso there video them swimming hunting too so they saying scientist lieinging for years crocodilian very aquatic advance to hunt fish .the first aquatic dinosaur spinosaurus i thought it was ceratosaurus whit his crocodilian tail the first popular won not so popular duck bill dinosaur it has duck face and crocodilian tail to tetanuran compsognathus type they are well known as aquatic there long tail is size of aquatic lizard the longest in dinosaur clearly hunt more on land same small snout ziphodont teeth nose point forward very fast leg the tibia is bigger than femur like fast animal horse and birds scipionxy fossil has fish in his stomach the same bad swimming tail as baryonyx if baryonyx is such bad swimmer it will still have those tail they will not become spinosaurus and have those crocodilian tail and Nile crocodile will never become gharial the most aquatic of modern crocodilian the best fisher the most advance eye elevation and tail .pterosaur allso aquatic very aquatic smooth skin it’s a dinosaur early pterosaur had serrated teeth they have tetanuran stiff tail very bipedal feature allso find in land crocodilian dwarf caiman one of them pterosaur heavy armor crown crest skull like voay crocodile duck bill dinosaur clearly it is flightless the advance pterosaur flexible tail like gator and none tetanuran.allso spinosaurus has less teeth than baryonyx most predator have less teeth crocodilian eat more fish have more teeth this spinosaurus type were killer of land animal more than fish .baryonyx relative short legs a aquatic feature spinosaurus legs was same size as baryonyx no science report support n.g. Report because forth trochanter science and it’s old science .palate science allso aquatic turtle palate almost close it has powerful bite. Pterosaur was a sting ray mimic

  • Spinosaurus nose is not on top of skull usual when you have whale nose that happen it’s more like a line it point forward most land animal have nose in front of skull spinosaurus nose is near eye it’s still aquatic feature it’s behind crocodilian baryonyx is same way too spinosaurus skull is a flat skull that not a land skull there are problem with flat skull hearing is bad spinosaurus skull same scientific name as dwarf caiman the skull is high crocodilian skull dwarf caiman hear like a mammal a land mammal it’s hearing is different from other crocodilian they call that good hearing but it’s not gator hear like whale because semi aquatic dwarf caiman is land crocodilian so hear like land mammal both are high tech dinosaur is primitive so can never here like modern crocodilian the most advance dinosaur .allso flat skull is weaker so it make no sense change from megaraptor to spinosaurus spinosaurus was aquatic it’s snout was thin allso weak feature good for fishing but not to kill animal with legs it’s mix use skull there the problem it must kill animal with legs no 6 bones fuse to braincase like the gator shorter palate they must find strenght so move the nose to eye even today modern crocodilian have stress problem there that why gator nose is fuse Nile crocodile is not so get more oxygen but it is weaker in eye place there no antorbital fenestra so spinosaurus reduce nose but smelling is bad that advitage modern crocodilian have they can make skull any shape strong that why they have more skull shape they can make short skull strong and can keep smelling .move nose have nothing do with aquatic in mesoeucrocodylia modern crocodilian fix spinosauridae skull problem.dwarf caiman have more room in skull so they fix hearing.they use gator with normal antorbital and spinosaurus spinosaurus skull break it did better reduce antorbital no change in gator because it has very wide snout a stronger snout Nile crocodile thinner snout a weaker skull .spinosauridae is animal caught in transition turn into modern crocodilian .dinosaur was fast like it’s descendants the gator the same way mammal was advance when they when into the water Same thing happen to dinosaur that why heart spleen kidney esophagus is of warm blooded animal .it’s true shore hunter have long skull a none tetanuran peg ankle dinosaur had the same skull it was shore hunter none tetanuran peg ankle dinosaur had whale nose crocodilian snout it was land animal .

  • I just read the paper they use reptile sail for spinosaurus which is wrong spinosaurus sail neural spine is like hump animal so did not have drag problem the sail is like American football like a fast fish tuna and snout is like fast fish barracuda mesoeucrocodylia can not have lizard type sail they are death roll animal even most primitive mesoeucrocodylia baryonyx has a death roll system most aquatic animal have big neural spine but all mesoeucrocodylia have big sail the extreme kind like spinosaurus it was like fish because spinosauridae was first mesoeucrocodylia mesoeucrocodylia just start it out since dinosaur allways fast animal and every animal get better because evolution spinosaurus has the gator tail it’s better swimmer than baryonyx more speed that what big sail is for more speed it’s primitive way get more speed early gator type mesoeucrocodylia did not have those monster ball joint that eusuchian has .but hunt fish like other aquatic animal they do not have those fast joint these joint are rare it was good at it so nature reward it with those monster joint the same way spinosaurus got that gator tail spinosaurus was fast but not as fast as modern crocodilian that why they are dead and gator is alive .baryonyx and spinosaurus live like the gator but more land base because mesoeucrocodylia was primitive at this time they did not live like dwarf caiman . We know dwarf caiman was bad swimmer because has tetanuran dinosaur tail did not like deep water but clearly baryonyx do they turn into spinosaurus and eusuchian .the reason why spinosaurus leg is like baryonyx when tibia is bigger than femur the forth trochanter must reduce like birds dinosaur mesoeucrocodylia . One gator type mesoeucrocodylia has the same feature. They think bird scar forth trochanter work like the gator.spinosaurus has unique aquatic teeth like early gator type mesoeucrocodylia those teeth are not found in modern crocodilian

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Queen Mary University of London

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