The Big Dinosaur Podcast

Episode 300 is all about Spinosaurus, the iconic predator from North Africa famous for its massive sail, huge crocodile-like head, and aquatic adaptations.

We also interview Nizar Ibrahim, paleontologist, anatomist, Assistant Professor of Biology at the University of Detroit Mercy, National Geographic explorer, and TED Fellow. He’s known for his work on Spinosaurus including describing the neotype and a recent paper showing a remarkably complete tail.

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In this episode, we discuss:

News:

• A new Deinocheirid, Paraxenisaurus, was described in Mexico source

The dinosaur of the day: Spinosaurus

• Spinosaurid that lived in the Cretaceous in what is now North Africa
• One of the largest known carnivorous dinosaurs
• Estimated to be up to 59 ft long (18 m) and weigh 20 tons, though new estimates from 2014 and 2018 suggested it could be between 49-52 ft long (15-16 m) and weigh 6.4 to 7.5 tonnes
• Comparable in size to T. rex, length-wise
• Had a long, low, narrow skull, similar to a modern crocodile (not short and high like other theropods with large bite forces)
• Had a narrow snout
• Tip of the top of the snout rounded up a little to fit the lower jaw, see this in crocodiles so they can grip smaller prey like slippery fish
• Complete snout from Kem Kem beds estimates skull length of 69 in (175 cm), skull length by Ibrahim and others was closer to 63 in (160 cm)
• Had a small crest in front of the eyes
• Tip of the snout was expanded (that had the large front teeth)
• Nostrils were high up, in front of the eyes, unusual for carnivores (nostrils in front of the snout)
• Nostril placement may be based on how Spinosaurus lived (semiaquatic)
• Had straight, conical teeth that were serrated
• Teeth couldn’t crush bone
• Teeth were narrow and sharp, and the largest teeth stuck out from the tip of the snout and the sides
• Had a long, muscular neck that curved in an S-shape
• Had large shoulders, and large, stocky forelimbs
• Had three fingers on each hand, with a large claw on the first digit of each hand
• Fingers were long and claws were somewhat recurved (hands may have been longer compared to other spinosaurids)
• Had a smaller hip bone compared to other large theropods
• Hind limbs were about 25 percent of the total body length
• Tibia was longer than the femur
• The fourth toe, hallux, touched the ground, unlike other theropods
• Toes had shallow claws with flat bottoms (similar to shorebirds, which may mean Spinosaurus feet were webbed)
• Lots of debate over how much time Spinosaurus spent in the water, will get to that
• Had neural spines on the back, that were about 5.4 ft (1.65 m) long, and probably connected by skin, making it sail-like
• Neural spines were a little longer front to back at the base
• Some scientists think instead of a sail the spines were covered in fat and formed a hump
• If a sail, would be a membrane of skin and thin tissue
• Ibrahim and others in 2014 suggested the spines were covered by skin, like a crested chameleon, and due to compactness, sharp edges, probably had poor blood flow
• Spinosaurus neural spines are much larger than neural spines of other spinosaurids
• Sail on the back may have been for thermoregulation or display (attract mates or intimidate rivals/make it look larger)
• If for thermoregulation, had lots of blood vessels, could have used the large surface area to absorb heat, so it didn’t overheat
• So large, effects of gigantothermy where its own body “insulates its internal parts from the outside cold”
• Or the sail/hump could help warm its blood enough to counter the cold waters it spent time in
• Spent time in river systems in North Africa in the Cretaceous
• May mean Spinosaurus lived in climates where night temperatures were cool and day not too cloudy
• Possible the sail radiated excess heat from the body, instead of collecting it (cooled it down)
• Bailey thought the sail could have absorbed more heat than it radiated, and suggested Spinosaurus and other dinosaurs with long neural spines had fatty humps to store energy, insulate, or shield from heat
• If for display, Ernst Stromer (who named Spinosaurus) thought the size of neural spines may have been sexual dimorphism
• Sail could also have been to attract mates
• Stromer compared neural spines to bison and some chameleons and other lizards (bison, spines covered in muscle and fat and form a hump); Stromer thought unlikely for a predator, probably a sail
• Spinosaurus was mounted in the Paläontologische Staatssammlung (more on the “was” later) with a short, very arc-ed sail. Then in 1936, Stromer rearranged the vertebrae to be longer, and the sail to have a more gentle slope
• Stromer at first thought it was hump-like “one might rather think of the existence of a large hump of fat [German: Fettbuckel], to which the [neural spines] gave internal support”
• Jack Bailey in 1997 supported the “buffalo-back” hypothesis and suggested Spinosaurus, Ouranosaurus and other dinosaurs with long neural spines had shorter, thicker neural spines to those found in animals with sails, and that the neural spines were similar to hump-backed mammals such as bison
• If a hump, could be to store energy
• If a hump, may have stored fat during seasons when fish swam upstream to spawn, could get by the rest of the year with less food (also Spinosaurus may have had to travel to search for fish for long periods)
• Hump could also be for display. Fat hump shows it was well fed, and a successful predator, more likely to be chosen as a mate
• Back to the sail idea
• Gimsa and others in 2015 suggested Spinosaurus sail was like the dorsal fins of sailfish and were for hydrodynamics
• Said the dorsal neural spines formed a roughly rectangular shape, similar to sailfish
• May have used its long narrow tail to stun prey like a thresher shark
• Sailfish herd schools of fish into a “bait ball” and trap the fish so they can snatch them with their bills (use as a screen to encircle the prey)
• Dorsal sail would help with sideways movements of the neck and tail, like sailfish and thresher sharks
• However, talked to Ibrahim about it in our interview about how different sailfish and Spinosaurus fins were
• Had short legs for its body
• Originally thought to be bipedal, now thought to be quadrupedal (at least facultative)
• May have crouched in a quadruped posture
• Ibrahim and others in 2014 found the hind limbs were shorter than thought, and center of mass was in the midpoint of the trunk region, not near the hip like in bipedal theropods, so thought Spinosaurus was poorly adapted for walking on land, and would be quadrupedal on land (pelvis was smaller than thought, which meant less space for large leg muscles)
• In 2018, Henderson found Spinosaurus was probably fine walking on two legs on land, and center of mass was close to the hips, and could be bipedal
• Had a long, narrow tail, with its own tall, thin neural spines and long chevrons (made a flexible fin or paddle-like structure)
• Used to think that the sail on the back extended to the sail on the tail
• As of 2020, Ibrahim and others found that the tail was deep and narrow, with a paddle or fin-like shape, like newts and crocodilians
• 2020 paper about the tail, describes neural spines and deep chevrons on the tail, which had a broad paddle shape
• Thin spines on the tail compared to the back, back spines are broad
• Tail spines thin in all directions and long (about ? the length of the spines on the back)
• Not a smooth transition, shortest spines just behind the hips
• Tail is asymmetric
• Top has long, thin spines
• Bottom has chevrons
• Flexible, ordinary tail on bottom, but tall and thin on top, tail vertebrae overlap less, so more flexible
• Tail was flexible and could move side to side, not stiff, so could have propelled itself through the water
• Bulkier tail may mean center of mass shifted back, bipedal walking easier (model show center of mass in front of the hips, but close enough to still be bipedal)
• The 2014 study by Ibrahim and others found Spinosaurus had dense bones, common in animals that swim a lot because greater bone density helps with buoyancy so it can swim under the surface
• Also found feet to be flat bottomed
• Originally thought to be bipedal, with tripod posture and a hump
• From the 1990s to 2014, Spinosaurus thought to be a long, lightly built theropod, with a sail or hump on the back
• The 2014 model had a crocodile-like skull and a sail on the back, and was an obligate quadruped
• Accuracy of 2014 model questioned, because it was a composite of different Spinosaurus individuals and other spinosaurids
• John Hutchinson warned that could result in inaccurate
• Scott Hartman thought the legs and pelvis were too short
• Mark Witton agreed with the proportions in the paper, after talking to Ibrahim and Simone
• Also debate on the size of the hind legs
• Baryonyx and Suchomimus thought to have hind legs like other theropods, but reconstructions are based on subadults and juveniles, so it’s possible hind legs shrank proportionally as it matured
• Also possible Spinosaurus was more advanced and specialized than other spinosaurids
• To recap: Spinosaurus had dense limb bones, long forelimbs, flat feet, tiny nostril high on the snout, short legs, large claws on its hands, elongated jaws, and conical teeth
• Also had flat feet, to walk over soupy substrate and not get stuck, possibly with webbing, and a sensitive snout, that could hone in on prey underwater
• And had a flexible tail that could propel it through water
• Based on all these characteristics, probably spent most of its time in the water
• However, as of the latest paper in 2020, still debate over Spinosaurus
• Mark Witton: “Our science on this unusual dinosaur is in its infancy, and forming robust ideas about its swimming pose and capability is going to take time.”
• 2018, Donald Henderson suggested Spinosaurus was not semiaquatic
• Created 3D models of Spinosaurus and other dinosaurs to test centers of mass buoyancy and equilibrium of animals in freshwater (Baryonyx, T. rex, Allosaurus, Struthiomimus, Coelophysis)
• Studied buoyancy in lungs of crocodilians as well and compared it to Spinosaurus lung placement, and found Spinosaurus couldn’t sink or dive below water surface, also able to keep its head above the water surface while floating, like other non-aquatic theropods
• Also found Spinosaurus had to paddle its hind legs to keep it from tipping over to the side, which extant semiaquatic animals don’t need to do
• Also modeled and tested model with Alligator mississippiensis and emperor penguin
• Found Spinosaurus could float with head above water, other dinosaurs had similar results
• Compared to alligator, which returned to original topside position when tipped to the side (semi-aquatic animals can self-right themselves)
• Spinosaurus model rolled over to side when tipped, so may have easily tipped over and would have to use limbs to keep upright in water
• Found center of mass in Spinosaurus to be closer to hips, similar to other theropods, and could walk on land
• Henderson then suggested Spinosaurus probably didn’t compete to hunt in water, but would have spent time on land or in shallow water
• Ibrahim, Pierce, Lauder, and Sereno and others in 2018 studied Spinosaurus tail and found it was keeled and well adapted to propelling it through water
• Found the elongated neural spines and chevrons meant it could swim in a similar way to modern crocodiles, could have been in the water for long periods of time to hunt
• Juvenile specimen found in 1999, described by Simone Maganuco and Cristiano Dal Sasso, found it developed semiaquatic adaptations at a young age or at birth
• About 5.8 ft (1.78 m) long
• Tail probably could help with propelling underwater (like modern crocodile, though not all scientists agree on this. Some think the thin bones at the end of the tail made it not as flexible as a crocodile’s, others think it being a stiff paddle under water could make sense, but that Spinosaurus wasn’t necessarily a predator that pursued prey often, and there could be other reasons for the weird tail)
• Vullo, Allain and Cavin in 2016 suggested spinosaurs would be able to adapt in the water like eels, based on convergence in shapes of jaws and teeth in Spinosaurus and pike conger eels, but didn’t say anything about Spinosaurus being semi-aquatic
• Probably lived in something like the mangrove swamps of today’s Florida Everglades
• Based on roots found growing from the lagoonal muds into marine sands, which only happens in mangrove swamps
• Mangroves: seawater that’s calm, temperatures are warm, low energy shorelines
• Lived in a humid environment with mud flats and mangrove forests
• Lived in a place covered with sprawling lakes, rivers and deltas
• Maybe Spinosaurus only came on land to lay eggs or move to a different river, rest of time in water
• Other dinosaurs that lived at the same time and place were titanosaurs Paralititan and Aegyptosaurus
• Other animals that lived in the same time and place included fish, crocodylomorphs, lizards, turtles, pterosaurs, and plesiosaurs
• Fish found in same fossil formations include lungfish, giant coelacanths, large sawfish like Onchopristis
• Probably ate fish
• Charig and Milner suggested Baryonyx ate fish, based on being similar to crocodilians (Baryonyx also found with fish scales and juvenile Iguanodon bones in stomach)
• A spinosaur tooth in a pterosaur bone in South America suggests spinosaurs also preyed on pterosaurs (maybe during dry seasons)
• Spinosaurus probably general and opportunistic predator, may be biased to fishing
• Probably scavenged and ate lots of small or medium sized prey (never give up a meal)
• 2009 study by Dal Sasso and others looked at foramina (small passages that lead to the same cavity in the snout), probably pressure sensitive receptors that could tell motions of fish when they swam through water (created pressure waves)
• Spinosaurus could know when fish were around and when was best to attack
• 2013, Andrew Cuff and Emily Rayfield found via bio-mechanical data that Spinosaurus was not an obligate piscivore and that diet was associated with an individual’s size
• Jaws were not adapted well to resist lateral bending, compared to Baryonyx and modern alligators, so probably ate fish more than land animals
• 2010 Romain Amiot and others did an isotope analysis and found that oxygen isotope ratios of spinosaurid teeth, including Spinosaurus, had a semiaquatic lifestyle (ratios were closer to those of turtles and crocodilians), so may have switched between terrestrial and aquatic habitats to compete for food with large crocodilians and other large theropods
• Oxygen isotopes showed exposure to aquatic environments for long periods of time
• Teeth were more widely spaced apart than other theropods
• Teeth interlock like a fish trap
• Teeth were for puncturing and tear
• Grab prey and yank head violently up and down, ripping out chunks” Hans-Dieter Sues
• Could be specialized to hunt for fish at the edge of rivers or to swim and hunt
• Higher nostrils mean could breathe while snout was in water
• Probably didn’t have a good sense of smell (but wouldn’t need it when going after fish)
• Type species: Spinosaurus aegyptiacus
• First discovered in Egypt in 1912
• Described by Ernst Stromer in 1915
• Genus name means “spine lizard”
• Spinosaurus aegyptiacus means “Egyptian spine lizard”
• Potential second species (long story): Spinosaurus maroccanus, which means “Moroccan spine lizard”
• Some scientists also think Sigilmassasaurus is a synonym of Spinosaurus (not everyone agrees)
• Holotype included ribs, gastralia, vertebrae, teeth, dentaries, left maxilla, neural spines
• Start at the beginning, with Ernst Stromer
• Stromer went to Bahariya Oasis in Egypt 1911
• Stromer’s first expedition in Egypt was in 1901
• Georg Schweinfurth founded the Royal Geographical Society of Egypt in the late 1800s, and was an archaeologist, geologist, and botanist, who discovered mammals and other fossils, which led Stromer to his first expedition in Egypt
• Some background on Egypt:
• Egypt was in a lot of debt and in 1876 formally declared bankruptcy
• A few years later, had a nationalist uprising, and Britain stepped in (Britain and France ruled as creditors)
• Then Britain ruled Egypt as a protectorate, solemnized in the arrangement the 1904 Entente Cordiale
• France got Morocco and Egypt went to Britain
• Stromer had to get permits from British authorities to dig
• November 7, 1910, landed in port of Alexandria, Egypt, but in quarantine for two days because someone on board suspected to have cholera, cargo unloaded, passengers still on board
• Ernst Freiherr Stromer von Reichenbach (baron, a gentleman), from Nuremberg in Bavaria
• He was an associate professor at University of Munich
• 40 years old, third expedition to Egypt
• Accompanied by scientists Dr. Leuchs, who brought his wife (Stromer not married yet and thought the journey too difficult with a wife)
• They did not get along
• Nov 9, got off the boat and Nov 10, they took a train to Cairo
• German geologist Karl Alfred von Zittel was a mentor and thesis advisor to Ernst Stromer
• He published the Rohlfs expedition, which produced a reliable, incomplete geological map of the Western Desert (which helped Stromer)
• In Cairo, Stromer went to Georg Steindorff’s office, a German Egyptologist, as a courtesy call and to help plan his expedition (Steindorff in 1901 had visited several oases of the Western Desert, including Bahariya)
• Nov 15: Stromer was missing Richard Markgraf, man from Austria who lived in the desert and collected fossils commercially and sold to paleontologists and museums, mostly in Europe
• Had worked with fossil hunters in the Gayoum
• Markgraf and Stromer met the winter of 1901-1902, and Markgraf was Stomer’s sammler, fossil collector, for a decade and a half, and a friend
• Markgraf was an itinerant musician then was ill and penniless in Egypt, set up as a commercial collector of fossils and other natural collectibles
• Before WWI, managed to ship fossils to Munich to prepare and study, but it was inspected and repacked poorly by colonial authorities, and badly damaged and didn’t get to Munich until 1922
• Markgraf kept collecting for Stromer during WWI (from 1911 until 1914), but conflict severed their contacts, and Markgraf died in 1916
• At this point, 1910, Markgraf was often sick, could be malaria, intestinal bleeding from typhoid or chronic amebic dysentery
• Stromer worried about him
• Stromer also got in an argument with Dr. Leuchs, and offered to provide him with half the expedition’s water containers and supplies so he could go on his own journey
• Tension between Germany and Britain, took a while for Stromer to get permits to go to the desert
• Finally left on his expedition Nov 18, with Markgraf
• Stromer was looking for early mammals in North Africa, like early whales and sea cows, and land mammals
• Thought mammals, including humans, originated in Africa, not Europe (not popular thought at the time)
• Stromer kept very detailed journals
• December 1910, and met his future wife (married in 1920, had three sons)
• Went back to Cairo Dec 21
• Markgraf was ill and couldn’t go with him to Bahariya Oasis (Stromer didn’t speak much Arabic)
• Budget for 1910-11 expedition was 18,000 German marks, including shipping (Stromer came from an aristocratic family, but was not that wealthy)
• Stromer needed a replacement for Markgraf, someone recommended gentleman Hartmann, took Stromer two days to locate him, didn’t get along
• Found a dragoman, a guide and translator, Mr. Mohammad Hasranin el Hitu
• Took Stromer a while to secure permits from British, French, and Egyptian authorities to travel the Western Desert
• New Year’s Eve 1910, took a train to Medinet el Fayoum
• Met Mohammad Maslin, a servant who had worked with him in earlier expeditions, hired him for the trip
• Didn’t trust the dragoman, he was a colonialist snob, didn’t like dragoman’s attempts to rise above “his station”
• Deep in the desert noon the next day
• Jan 11, Bahariya, found dinosaurs
• Had his base of operations in Mandisha, in the Bahariya Oasis
• There was a sandstorm, explored and didn’t find much
• Jan 14, 1911, Stromer found three large bones, cut up mosquito netting and soaked them in a flour and water paste, to cover the two larger bones
• Or maybe Jan 18? (conflicting sources), found “three large bones which I attempt to excavate and photograph.” found more bones, including a “gigantic claw”
• Wrote in journal, “Apparently these are the first of Egypt’s dinosaurs and I have finally before me the layer that contains land animals.”
• Didn’t know how to preserve and collect them, logistics
• Desert is destructive for exposed fossils
• Feb, packed up specimens in eight wooden crates, with help of Markgraf who recovered, and arranged to ship to Munich
• Home in Munich by Feb 23
• Markgraf kept excavating fossils in the winters of 1912 and 1913
• Markgraf found a partial (what would be named) Spinosaurus skeleton in 1912 in the Bahariya Formation, in western Egypt
• On Stromer’s instructions, Markgraf closed excavations April 1914 and returned to Cairo to ship them to Munich
• It was about a month before WWI
• Markgraf had a hard time getting Anglo-Egyptian authorities to cooperate, they distrusted Markgraf and Stromer, because Stromer was German
• Markgraf would only get paid once the fossils were delivered successfully
• After the war broke out, Stromer wrote to British and Egyptian authorities begging for his fossils, but to no avail
• Markgraf died, and his wife was desperate and wrote to Stromer
• Stromer appealed to his British friends at the Geological Survey of Egypt, and they paid Markgraf’s widow a fee and took the 12 cases of fossil material for safekeeping
• Stromer got the fossils in 1922
• Meanwhile, Stromer wrote monographs on the geology of the Bahariya Oasis and pieced together fossils Markgraf had shipped in 1912
• In 1915, he published on Spinosaurus aegyptiacus
• In WWI, Stromer served as a male nurse (had medical training), then became military geologist at the Geological Survey in Strasbourg, which was German territory, his geological skills valuable to tactical planners
• Returned to Munich Nov 1, 1919 and got an appointment to the Bavarian State Collection of Paleontology and Historical Geology
• After the war, there were food shortages in Munich, food riots, violence, so Ernst Stromer went home to Nuremberg
• Winter of 1919 to 1920, taught at the city’s commercial college, and retreated to family’s nearby castle and estate that had food because of lands and farm
• Oct 1920, back to Munich with wife, Elizabeth Rennebaum, and promoted to chief conservator of the Bavarian State Collection of Paleontology and Historical Geology, nine months later, honorary professor of paleontology at University of Munich, July 23, 1921, became a full member of the Bavarian Academy of Sciences
• Worked with international scientists to get his fossils from Egypt, but because of inflation, Stromer couldn’t afford to ship them, a former pupil of his Bernhard Peyer paid Cairo officials to have the crates shipped, arrived in the summer of 1922
• But the fossils were “Hence everything,” Stromer later reported, “was rather badly smashed up.”
• Cairo, staff at the museum of the Geological Survey had unpacked and examined the fossils, and done a poor job repacking them
• Stromer knew he probably wouldn’t go back to Egypt (Markgraf dead, and Stromer poor b/c of Germany’s conditions)1936, Stromer provided a reconstruction of Spinosaurus, with a sail and a skull similar to a megalosaur or allosaur, though he knew it had a peculiar lower jaw
• Stromer compared to crested chameleon for neural spines/sails
• 8ft+ sail, elongate trunk, massive forelimbs, long neck, long skull
• May have been quadrupedal on land
• Stromer Riddle: multiple carnivores in the area, yet the carnivores didn’t compete for prey. How was this possible?
• Spinosaurus wall mounted at Paläontologische Staatssammlung at Munich
• Then Nazis came to power
• Stromer openly resisted the Nazi regime
• Stromer was an aristocrat, which protected him
• 1930, Stromer was head of the paleontology section of the Bavarian State Collection of Paleontology and Historical Geology
• His career stalled out, because he didn’t join the Nazi Party and he spoke out against Nazis and kept close relationships with Jewish friends and associates
• July 7, 1937, he was 65 and forced to retire from the university and State Collection
• Stromer stayed in Munich and remained a fellow of the Bavarian Academy of Sciences, kept doing research and publishing papers
• Nazis made sure every institution in Germany was headed by loyal party members
• This meant the director of the Bavarian State Collection post went to Karl Beurlen in 1940, when Stromer’s friend Ferdinand Broili reached mandatory retirement age
• Beurlen was an ardent Nazi
• Stromer kept demanding Beurlen to remove the Bavarian State Collection from the museum at the Alte Akademie and put it in a protected location far from Munich
• Beurlen kept dismissing him, believing Germany or Munich would not be attacked, based on Luftwaffe chief Hermann Goring
• Even when fine art and science museums throughout Germany removed collections to caves and salt mines, Beurlen didn’t change his mind
• Broili, still emeritus at the museum, quietly removed small specimens from the museum in his briefcase
• Broili stored them in Princess Theresa zu Oettingen-Spielberg’s castle, an ally (paleontologist and noblewoman), but couldn’t transfer a lot of the collection
• Stromer kept demanding, and Beurlen threatened Stromer at least twice with moving him to a concentration camp
• Beurlen reported Stromer to Nazi authorities, but they didn’t take direct action
• Stromer had three sons: Ulman, born 1921, Wolfgang, 1922, Gerhard, 1927
• Ulman and Wolfgang were sent to the Russian front as soon as they were conscripted
• Ulman killed Nov 10, 1941
• Wolfgang survived until Nov 1944, then disappeared in Russia
• Stromer and wife by then retreated to Grunsberg, and Apr 24, 1944, he learned of the Royal Air Force bombing in Munich that destroyed his life’s work
• April 25, 1945, Gerhard died within months of being assigned to a battalion fighting Allied forces in northern Germany. Less than two weeks after his death, Germany surrendered
• Royal Air Force (RAF) bombing of Munich happened, and ended 1:40 AM on April 25
• More than 200 Lancasters dropped hundreds of bombs, more than 7,000 buildings near the train station were in flames
• Museum was on fire, collection destroyed, including Stromer’s Spinosaurus
• Though there are still detailed drawings and descriptions

• After WWII, paleontologists were more conscientious about making casts of fossils in case the originals were destroyed
• Stromer was not in Munich at the time, had moved away to his family’s lands
• Ernst Stromer still wrote and published scientific monographs into his late 60s
• May 5, 1950, Wolfgang (who was referred to as “missing” at the Russian front during WWII) returned. He was a physicist and Russians kept pressuring him to help produce poison gas after they captured him. He refused, and was put in multiple prison camps in Siberia for years
• Stromer was 80 when Wolfgang came home, and Stromer lived long enough to learn Wolfgang and his wife, Heidrum Ruhle, would have a daughter, Rotraut
• Dec 18, 1952, Stromer died, age 82
• Not much known about Spinosaurus for many years
• Spinosaurid remains first identified as spinosaurid in Tunisia (Lower Cretaceous) in 1988, though reptile fossils found in 1912 by Pervinquière, and dinosaurs reported by Lapparent in 1951
• Teeth are different, and thought to be other reptiles (1978 thought to be plesiosaur teeth by Schlüter and Schwarzhans)
• In 1987, drawings of the Spinosaurus holotype were compared to Baryonyx, which had a crocodile-like skull
• In 1998 Suchomimus was described and named, from Niger, and had tall neural spines
• International expedition in the Sahara desert in 1995 found more Spinosaurus fossils in the Kem Kem region, including isolated teeth and fused nasals
• Dentary fragments, cervical vertebra and dorsal neural arch found in the northern part of the Kem Kem region, led to Dale Russell naming Spinosaurus maroccanus in 1996
• Russell and Torquet described a partial snout in 1998
• (Again, the validity of Spinosaurus maroccanus is debated)
• Other Spinosaurus material included in 2003 when Milner described incomplete snout and left dentary that was at the Natural History Museum of London
• 2005, Dal Sasso and others reported a snout found by locals in 1975, said it was Spinosaurus aegyptiacus
• But before we get to 2005, we have to go back to Spinosaurus in 1999
• Jan 1999: Jennifer Smith, doctoral candidate in Penn’s Department of Earth and Environmental Science, was studying geology of Egypt’s Bahariya Oasis (180-190 mi from Cairo), for evidence of climate change and hominid and human habitation
• She brought along fellow doctoral student Joshua Smith (and her fiancé) to accompany her for 5 weeks, because she needed a male to be with her in a Muslim country (her dissertation advisor couldn’t make it that year)
• Josh Smith was a trained sedimentologist, who’d always wanted to see Egypt (the year before, Josh and Matt Lamanna tried to find a way to go, Lamanna knew nobody was working in the area and Stromer had found a lot of fossils there)
• He was 29 years old at the time
• Josh Smith studied vertebrate paleontology and needed a reason to go to get his PhD advisor Peter Dodson to agree to the trip
• Jen’s research site passed through where Ernst Stromer von Reichenbach had found Spinosaurus
• Josh negotiated and settled on three days of the 5 week trip to search for “Stromer’s lost dinosaurs”, but had low expectations (no maps or known photographs of the sites, but there were notes about where he excavated, descriptions of landforms)
• Got lucky, and found a bone, 10 in in diameter and 1 ft long on the first morning while driving around, found 20 accumulations of bones by the end of the first day
• In a day found Gebel el Dist, a distinct landform, Stromer’s isolated cone-shaped hill, found lots of bones
• Josh needed funding to go back for more excavating
• Before WWI, most scientific expeditions funded by wealthy patrons, not governments, and small grants from universities or scientific societies
• Back in Philadelphia, Josh had drinks with R. Scott Winters, a PhD candidate in biology, involved in the Explorers Club (founded 1904 to promote field research and scientific exploration), and partner in a film production company that made science and expedition based documentaries
• Got a deal with $50,000 to fund the first field season Jan-Feb 2000 in exchange for rights to make the documentary in association with Winters’ company, Last Word Productions
• Made the film, premiered in 2002, The Lost Dinosaurs of Egypt
• With funding, had 21 people, and excavated for 6 weeks
• Included Josh Smith, Jen Smith, Peter Dodson, Matt Lamanna, Kenneth Lacovera, Jason Poole, and volunteers, as well as film crew
• Bob Giegengack, Jen’s PhD advisor, had a network working as a geologist in Egypt, and they formed a partnership with Cairo Geological Museum and the Egyptian Geological Survey and Mining Authority for exclusive excavation rights in the Bahariya Oasis for five years
• Agreed to half of the excavated fossils to go to Philly, other half to stay in Cairo
• Arrived in Egypt Jan 11, 2000
• Set up headquarters at El Beshmo Lodge, “cushy” had hot showers almost every day, toilets that flushed, rooms with tile floors, someone cooked them food
• Jen Smith said in an article, “Normally we work based out of a mudbrick hut with a dirt floor and a pit toilet and there’s no running water. That’s what I’m used to”
• First few weeks were cold, high 30s-low 40s with strong winds
• Then the end temps were 85-90 degrees
• Had three sandstorms in two weeks
• Team got food poisoning in between sandstorms, before they found much
• Think they found some of Stromer’s original sites “We found what are very obviously excavation pits that had been filled in with sand blown in by the wind, in some cases burlap” which, soaked in plaster, was wrapped around fossils for protection during transport, “and even in one case a little scrap of newsprint with German writing on it.”
• In the desert with the wind, may see one bone but then you dig and there’s nothing else (pattern)
• Jan 27, found more, a humerus that was 67 in and part of another (sauropod, Paralititan)
• By the end, had excavated a quarter of the skeleton
• Matt Lamanna also found, half a mi from the sauropod site, non-dinosaur material including turtle shell, fish jaws, and stuff to help show the environment. Named it Jon’s Birthday Site, in honor of his brother Jon, born Jan 27
• After, Josh Smith and Matt Lamanna went to Munich to look for more evidence to help with future excavations
• Stromer’s son Wolfgang donated Stromer’s archives to the Paleontological State Collection of Munich in 1995
• Josh and Matt went through Stromer’s diaries
• Found more than 100 glass-plate negatives of Stromer’s specimens
• One showed a partial skeleton of Spinosaurus, mounted in a glass case in the museum (before that, people didn’t realize Spinosaurus had been mounted before it was destroyed)
• Found evidence that Stromer was not a Nazi sympathizer
• Also found two photographs of the holotype
• Based on a photograph of the lower jaw, and a photo of the mounted specimen, Smith said the 1915 drawings were a little inaccurate
• Oliver Rauhut in 2003 said Stromer’s holotype was a chimera, with vertebrae and neural spines from a carcharodontosaurid similar to Acrocanthosaurus, and a dentary from Baryonyx or Suchomimus, but not everyone agrees
• Cosmos Studios and MPH Entertainment planned a sequel documentary before the first one aired
• Team went for a second field season
• Quarry known as Jon’s Birthday site had lots of diversity in fossils
• Fossils were in hard sandstone, hard to excavate
• On one of their expeditions, Josh Smith and team found one of Stromer’s sites, which Markgraf had excavated
• They were backfilled pits, maybe because whoever dug them ran out of time or money or both and wanted to preserve whatever was in there until they could return, could be Markgraf’s last site
• Now fast forward to 2008
• Nizar Ibrahim was on a fossil hunt expedition in Morocco, a man in a town near Erfoud showed him bones in a cardboard box. Ibrahim arranged for them to go to the University of Hassan II in Casablanca
• In 2014, Ibrahim went to Italy on a small doctoral student budget after Cristiano Dal Sasso contacted him (on the fossils the museum had gotten in 2006), saw bones in Milan museum’s basement of Spinosaurus; saw a distinctive pattern on the bones he remembered seeing in Morocco
• Museum bones Ibrahim looked at in Milan had been found in 1975, originally thought to be the lower jaw of a crocodile, but they were part of Spinosaurus snout
• Fossils collected by amateur fossil hunters, sold to collectors on the private market (teeth, vertebrae, partial skull found in North Africa post Stromer)
• Natural History Museum in Milan, Cristiano dal Sasso had gotten a large collection of bones from an Italian fossil trader, told they’re from Morocco, likely spirited out illegally
• Seem to be from a single specimen
• Included all spines, leg bones, foot bones, skull fragments, more fossils than Stromer’s Spinosaurus (60 bone fragments)
• Ibrahim moved the fossils to the University of Chicago, Paul Sereno’s lab, to be studied
• Not clear where the bones are from/originated
• Ibrahim noticed the cross section of the spines had unusual lines, maybe fossilized traces of blood vessels (not clear what they are)
• He remembered he had seen a similar pattern in Morocco in 2008, and wondered if he could track down the fossil hunter to compare and to learn where the fossils came from
• All he remembered of the man was he was tall, had a mustache, and wore a white tunic
• Ibrahim flew back to Morocco to find the man
• With help of Dave Martill and Samir Su(?), Ibrahim went village to village, shop to shop, chatting to locals for clues to fossil hunter’s whereabouts
• Morocco has vague export laws, and fossil diggers are allowed to trade and sell all common fossils (dinosaur teeth, trilobites,) but it’s illegal to export rare fossils out of Morocco
• Diggers have no special training, bore tunnels, often damage fossils, don’t document rocks or where something came from, no support structures, soft sandstone, people have died, breathe in dust
• Diggers depend on income, paleontologists depend on diggers
• On his second to last day in Erfoud, was sitting at a cafe sipping mint tea, giving up, and a tall, white-clad figure walked past his table, and he recognized his face, ran after him, convinced him to show the cave where he’d found the bones (the man was worried about getting in trouble that the skeleton is illegally abroad, so he remains unidentified)
• Ibrahim and the man drove an hour off-road, then trekked up mountain for 30 minutes, to a nondescript hole in the hillside
• Dig site had fragments of bones and teeth, most likely Spinosaurus
• Dealer said it took 2 people digging 2 months to get skeleton out, sold it to Italian fossil dealer for $14,000 USD
• The site gave info about Spinosaurus environment
• Paul Sereno, Dal Sasso, and colleagues from UK and Milan went to excavate, and to characterize rock and landscape to see when and how Spinosaurus lived
• Found fossils with the same unusual patterns, confirmation it’s the same specimen
• Also found sea urchins and mollusks, marine animals, shellfish
• Not many herbivores found in the area, but many types of carnivores/predators
• Back to Stromer’s Riddle
• Sawfish, lungfish, coelacanths, are in the fossil record, could feed Spinosaurus
• Idea that Spinosaurus was built to catch fish
• After the expedition, Ibrahim and team CT scanned all the bones, to make a 3D model
• Tyler Keller assembled to a virtual Spinosaurus
• Added the missing parts, based on Stromer’s figures/drawings, as well as scans of Suchomimus for the skull (braincase, for example)
• Spinosaurus went from 40 to 60% complete with scaling and other dinosaur parts and isolated bones
• Lots of controversy on Ibrahim’s 2014 paper on Spinosaurus, Ibrahim also published on Spinosaurus’ tail in 2020. Diving in
• 1934, Stromer described specimens, including long bones, vertebrae, some teeth, that he thought was a single taxon, he called Spinosaurus B, but said parts of an ilium and leg bones were too small to be part of the same individual as the rest of the material (found the teeth, vertebrae, and gastralia on one side, and the long hindlimb bones on the other side belonged together), though this has been questioned (and material is lost from WWII
• Stromer thought it was a new species of Spinosaurus but didn’t like naming dinosaurs based on fragments. “I refuse to participate in the abuse of coining new genus and species names on the basis of such isolated and totally incomplete remains, which then, due to the, for palaeontology completely inadequate, priority rules of nomenclature and their senseless pedantic application, will have to be used for further nomenclatorial acts” (why he went with “Spinosaurus B”)
• Stromer also described another specimen in 1934, but briefly, no illustrations or photographs found (three cervical vertebral centra, two half neural arches, mid-section of an elongate dorsal neural spine, two ribs, possible distal fibula), described as having similarities to Spinosaurus B and Spinosaurus aegyptiacus (not enough information now to study)
• Kem Kem region of south-eastern Morocco has many predatory dinosaurs, including Spinosauridae
• Dale Russell named one Sigilmassasaurus brevicollis in 1996, which has been interpreted as Carcharodontosaurus saharicus, then Spinosaurus maroccanus, then Spinosaurus aegyptiacus
• Russell later proposed Spinosaurus B was Sigilmassasaurus (nearly identical to bones from early Late Cretaceous sediments in Morocco)
• Dale Russell described Spinosaurus maroccanus in 1996 based on the length of the neck vertebrae (said it was longer than Spinosaurus aegyptiacus)
• Some scientists think this is due to individual variation, but the holotype of Spinosaurus was destroyed and can’t be compared directly with the new species
• They think Spinosaurus maroccanus is a nomen dubium or a junior synonym of Spinosaurus aegyptiacus
• Ibrahim and others in 2014 designated a neotype of Spinosaurus aegyptiacus and said Sigilmassaurus and Spinosaurus B were Spinosaurus aegyptiacus and that Spinosaurus maroccanus was nomen dubium
• In 2015, Evers and others said Sigilmassaurus was a distinct genus, supported in 2018 by Arden and others (as a close relative of Spinosaurus)
• They said there was more than one spinosaurid taxon
• Said proportions of hind limbs were shorter than previous reconstructions (based on Ibrahim’s description, Spinosaurus had shorter hind limbs than previously thought)
• Also found Sigilmassaurus had shorter neural spines than Spinosaurus
• Also about the Spinosaurus aegyptiacus neotype:
• parts of the skeleton were purchased in 2008 by University of Casablanca; other parts acquired in 2009 by the Museo di Storia Naturale in Milan; authors then located the collector, who showed them the locality. They excavated and found more parts of the neotype
• Some scientists suggested because it wasn’t made clear which fossils came from where, or evidence that material all came from same place and was from the same individual, hard to make it the neotype
• Then Ibrahim and others published their 2020 paper on Spinosaurus: Ibrahim returned in 2015-2019 and found “new fragments of the cranium and mandibles, several previously missing bones of the left and right pes” an 80% complete tail (by length)
• Part of the proposed neotype
• Estimated at least 15 years old, based on 10 LAGS in the fibula, and estimate 5 more probably there before (ribs had similar number of LAGs), spine had fewer, may have grown sail taller as it aged
• Ibrahim has said he’s hoping this might help get a Moroccan national museum of natural history built
• Museums are great at getting local support for paleontology
• Can see Spinosaurus in Jurassic Park III, where it had more typical theropod skull
• Jack Horner said, “If we base the ferocious factor on the length of the animal, there was nothing that ever lived on this planet that could match this creature [Spinosaurus]. Also my hypothesis is that T. rex was actually a scavenger rather than a killer. Spinosaurus was really the predatory animal.”
• He has since retracted his statement that T. rex was a scavenger
• Also on postage stamps from Angola, The Gambia, and Tanzania

Fun Fact: Spinosaurid fossils have been found on 4 continents, Africa, Europe, Asia, & South America. None have been described from North America, Australia, or Antarctica.

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