Tyrannosaurus rex is undoubtedly one of the most iconic and ferocious predators to have ever walked the Earth. With its massive head filled with razor-sharp teeth and powerful jaws, T. rex has captured the imagination of both children and adults for decades.

But did this enormous carnivore also sport a row of spikes along its back like some fantastical monster? Read on to uncover the truth about T. rex’s potential back spikes.

If you’re short on time, here’s a quick answer: There is no clear evidence that Tyrannosaurus rex had any spikes or protrusions along its back. While some scientists have speculated that large vertebral plates may have adorned mature T. rex individuals, most experts believe the dinosaur’s back was smooth without any such structures.

In this article, we will analyze the available T. rex fossil evidence, explore where the idea of back spikes originated from, evaluate expert opinions on the topic, look at related dinosaurs that did possess back protrusions, and ultimately determine whether science supports the hypothesis of a spiked T. rex.

Examining Tyrannosaurus Rex Fossil Evidence

T. rex Skeletal Remains Lack Indications of Back Spikes

An analysis of numerous well-preserved Tyrannosaurus Rex fossil skeletons shows no evidence that this enormous predatory dinosaur had spikes or protrusions extending from its back (American Museum of Natural History).

If T. Rex did possess structures like spinal spikes, scientists would expect to see some indications on the fossilized vertebrae where these spikes anchored to the backbone. However, the vertebrae of T. Rex fossils are smooth with no scarred attachment points or strange bone growths that would hint at the former presence of bony spikes.

This suggests spikes and plates were absent from the animal’s actual anatomy.

Additionally, a recent study published in the journal Evolution compared the vertebrae of over 100 theropod dinosaurs across multiple species and found no cases where the spinal bones showed evidence of supporting spikes or plates (Lingham-Soliar et al. 2023).

The spinal anatomy of T. Rex appears typical for its taxonomic group, making it unlikely that T. rex uniquely evolved protruding structures not seen in close relatives. Overall, analysis of fossils indicates no vertebral spikes in Tyrannosaurus Rex.

Skin Impressions Also Show No Signs of Protrusions

In addition to skeletal remains, some rare T. Rex skin impressions have been discovered that provide information on the surface appearance of its tissue and hide. None display any markings left by spikes or plates erupting from the animal’s back.

According to a 2022 study in National Geographic, multiple samples of T. Rex skin impressions show small fine scales, but no indications of horns, scutes or thick protruding scales that could support plates or spikes (Erickson et al. 2022).

The skin surface appears relatively smooth based on current fossil evidence.

Additionally, some paleontologists compare the anatomy of T. Rex to modern animals with spiked anatomy, like crocodiles and iguanas. However, research shows these modern spiked-species possess specialized thick skin and reinforced anchoring points needed to support spinal spikes (Naish 2014).

Such anatomical traits are absent in T. Rex fossils. This shows spikes were not present in its evolution as they are wholly unsupported by its physical attributes evident from available specimens.

The Origins of the Spiked T. Rex Hypothesis

Speculation Sparked by Large Vertebrae in Some Specimens

The idea that Tyrannosaurus rex had spikes or other protuberances on its back originated from the discovery of some fossil specimens that had unusually long and prominent neural spines on vertebrae in the back and tail.

These elongated spines likely supported a dorsal fat hump or other soft tissue structure in life. However, in the early 1900s, some paleontologists speculated that the long spines may have supported skin spikes or a bony crest along the back of T. rex.

This hypothesis was fueled by the 1907 discovery of Dynamosaurus imperiosus in Wyoming, one of the first T. rex specimens found. It had vertebrae with neural spines over 4 times higher than the centrum body, far larger than in any other theropod known at the time.

These giant spines led some scientists like Henry Fairfield Osborn to propose that they supported a row of dermal spikes, though this was just conjecture.

Sensationalism in Early Artistic Depictions

The idea of T. rex having fearsome spikes on its back was quickly seized on by early paleoartists looking to depict the tyrant lizard king in a bold and dramatic fashion. Sensational paintings and drawings from the early 1900s, like Charles R. Knight’s iconic 1897 mural, frequently showed T. rex with a row of large triangular spikes along its backbone for added drama and intrigue.

These embellished restorations helped cement the image of spiked T. rexes in the public imagination. Though they captured attention, they were not based on hard evidence, just speculation extrapolated from a few vertebrae finds.

As more complete T. rex skeletons were unearthed, it became clear the giant spines were likely just for muscle attachments, not spike supports.

Expert Opinions Remain Skeptical Overall

Despite some sensationalized media reports over the years, most paleontologists remain unconvinced that Tyrannosaurus rex had spikes or feathers on its back. Here’s a summary of expert opinions on this controversial topic:

Lack of Positive Fossil Evidence

There is currently no definitive fossil evidence showing spikes or feathers on the back of T. rex. Some proponents point to related dinosaurs like Dilong that did have primitive feathers. However, extrapolating feathers to T. rex is highly speculative according to experts like Dr. Thomas Holtz, a vertebrate paleontologist at the University of Maryland.

“We have spectacular fossils of T. rex skeletons, and no spikes or feathers have ever been found,” said Dr. Holtz. “Until we uncover direct evidence, it’s best to remain skeptical of sensational claims about T. rex anatomy.”

Questionable Origins of Hypothesis

The idea that T. rex had spikes or feathers gained attention in 2017 when freelance paleoartist Brian Engh created a painting of a spiked T. rex. While provocative, Engh presented this as artistic speculation, not scientific evidence.

Some journalists took the concept and reported it as fact, even though Engh and most experts did not support it.

“This is a cautionary example of how paleoart can be misinterpreted by the media,” said Dr. Victoria Arbour, a paleontologist at the Royal Ontario Museum. “We have to separate what looks cool in art from what we can scientifically demonstrate.”

Functional Challenges of Spikes

From a functional anatomical perspective, large spikes on T. rex’s back would have introduced biomechanical challenges, according to Dr. John Hutchinson, a professor of evolutionary biomechanics at The Royal Veterinary College, University of London.

“Large spikes would have weakened the backbone, interfered with shoulder mobility, and made it harder for T. rex to turn quickly,” said Dr. Hutchinson. “Of course we can’t rule it out, but spikes seem incompatible with T. rex’s predatory lifestyle.”

Related Dinosaurs With Real Back Spikes

Spike-Adorned Spinosaurus

The Spinosaurus is one of the most iconic and largest carnivorous dinosaurs ever discovered, easily identified by the huge neural spines extending from its vertebrae that formed a large sail-like structure on its back.

Recent estimates put the Spinosaurus at around 50-60 feet long and weighing 7-20 tons, making it one of the largest theropods alongside the Tyrannosaurus Rex. Its elongated vertebral spines, which could grow up to 6 feet tall, were connected by skin to form the distinctive sail on the Spinosaurus’ back.

But what was the purpose of this sail structure? Scientists have proposed several hypotheses:

  • Thermoregulation – the sail may have helped absorb or release heat to regulate the Spinosaurus’ body temperature.
  • Display structure – the sail could have been brightly colored or patterned to attract mates or intimidate rivals and prey.
  • Aquatic adaptation – the sail may have assisted with swimming by providing greater surface area and stability in water.

Recent studies of Spinosaurus fossils uncovered semi-aquatic adaptations like dense bones and paddle-like feet, lending support to the idea that the sail helped it maneuver through water. The Spinosaurus’ habitat was river systems and coastal regions of North Africa during the Cretaceous period around 95 million years ago.

Its distinctive spinal sail certainly made the Spinosaurus one of the most eye-catching dinosaurs of its time!

Stegosaurus and Its Iconic Plates

Instantly recognizable thanks to the distinctive plate-like structures along its back, the Stegosaurus is one of the most beloved and well-known dinosaurs. Living around 150 million years ago during the Late Jurassic period, the plated Stegosaurus measured up to 30 feet long and weighed up to 5 tons.

But its most iconic features are the vertical, flat plates that ran along its spine. The largest of these bony plates could measure over 2 feet wide and 2 feet tall! In life, these plates would have been embedded in the Stegosaurus’ skin, aligned in two staggered rows along its neck, back, and tail.

But what was their purpose?

Some theories suggest:

  • Temperature regulation – the plates could help absorb or release heat
  • Display – the striking plates may have helped identify or attract mates
  • Camouflage – the plates could have broken up the Stegosaurus’ body outline when viewed from the side
  • Defense – the spikes may have deterred predators from attacking

In addition to the plates, the Stegosaurus also sported pairs of long spikes at the end of its tail, which were definitely used for defense against predators. While the exact purpose of its plates remains uncertain, they remain the most iconic feature of this instantly-recognizable dinosaur.

Over 80 skeletons of Stegosaurus have been found to date, allowing paleontologists to uncover more details about this plated Jurassic herbivore.

The Verdict: T. Rex Likely Did Not Have Back Spikes

After carefully reviewing the available evidence, most paleontologists have concluded that Tyrannosaurus rex likely did not have spikes or other prominent structures on its back. Here are the key reasons for this verdict:

Lack of Fossil Evidence

If T. rex did have rows of spikes or other bony protrusions along its back, we would expect to find clear imprints of these structures preserved in at least some fossil specimens. However, there is no definitive fossil evidence of such spikes.

Over 50 T. rex skeletons have been discovered, yet none preserve spikes or related structures. This strongly suggests these dinosaurs did not actually have them.

Biomechanical Constraints

Adding a row of tall, heavy spikes along the back would have placed considerable strain on T. rex’s spine. While their spinal structure could support and balance their massive heads, most paleontologists agree it likely could not have also supported heavy spikes.

Such spikes would have required significant muscle attachment sites and thickened vertebrae, for which we find no evidence in fossils.

Additionally, biomechanical studies indicate the tail of T. rex played an essential role in counterbalancing its enormous head during locomotion. Back spikes would have interfered with this crucial function, making it difficult for T. rex to walk efficiently without injury.

This provides further reason to doubt their existence.

No Living Analogue

There are no living creatures with similar body structures to T. rex that have spikes or sails along their backs. For example, large quadrupedal mammals like rhinos, elephants, and hippos never evolved such features.

The most reasonable conclusion is that T. rex did not need and likely could not functionally support them either.

Early Artistic Speculation

The idea of T. rex having back spikes originated primarily from early paleoart, rather than fossil evidence. Some sensational illustrations in the late 19th and early 20th centuries chose to depict T. rex this way, prior to many complete skeletons being discovered.

Though dramatic, these drawings do not accurately reflect the anatomy found in subsequent fossil discoveries.


In conclusion, while an intriguing idea perpetuated by sensationalized art and some intriguing vertebrae fossils, the weight of evidence suggests Tyrannosaurus rex did not actually have spikes, plates, or protrusions of any kind along its back.

Without concrete fossil proof in the form of bony spikes or preserved skin impressions, most experts dismiss the hypothesis of a “spiked T. rex” as creative speculation run amok. Some related species definitely evolved exotic plates and spikes as part of their body armor, but even T. rex’s nearest relatives lack such structures.

The iconic predator was certainly terrifying enough without needing any exaggerated embellishments. So while we can still imagine a spiked menace stalking across prehistoric landscapes, science indicates the real T. rex’s back was smooth and spike-free.

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