Biologists Just Found Out What Thylacines in Tasmania Actually Are

Summary

A study of thylacine skulls suggests that the animal’s wolf-like appearance concealed a very different hunting design. Rather than being a wolf-like predator built to chase or wrestle large prey, the thylacine may have been a small-bodied ambush hunter with an unusually large skull and a long, fast-closing jaw. The findings also call into question the traditional claim that thylacines were major livestock killers.

Findings and scientific concepts

• The thylacine may have survived beyond 1936. The last known captive animal died at Hobart’s Beaumaris Zoo on September 7, 1936. A later statistical analysis of reported sightings and other records suggests wild thylacines may have persisted for years or decades afterward. The researchers cited in the video consider survival to the present highly unlikely.

• A famous photograph helped shape the thylacine’s reputation. A 1921 image showed a thylacine-like animal holding a chicken and was presented as a photograph taken in the wild. The glass negative had been cropped to remove a cage. Researchers disagree over whether the animal was alive in captivity or a mounted specimen, but the image helped reinforce the idea that thylacines were poultry killers.

• Its body was smaller than many older accounts suggested. A 2020 estimate based on museum specimens put the average adult’s mass at about 17 kg, rather than the roughly 30 kg often cited in older books. Despite its relatively small body, the thylacine had a skull about as large as a wolf’s.

• Its skull did not match any living mammal in the comparison. Researchers compared three-dimensional scans and digital reconstructions of 225 skulls from 14 carnivorous mammal families. Wolves had the right general size but sturdier snouts, while foxes and related animals had more similar snout shapes but much smaller skulls. The maned wolf was the closest mammalian match in combined size and shape, but still differed substantially.

• The jaw suggests a rapid, forceful strike. The thylacine had a long, slender snout, an unusually tall jaw, and a flared area around its upper canine teeth known as a terminal rosette. Researchers compared this arrangement mechanically to the long, fast-closing jaws of crocodilians and some predatory fish. The proposed similarity concerns how the jaw works; it is not evidence that thylacines hunted fish.

• The large skull may have helped absorb bite forces. A long, slender jaw can move its tip quickly, helping catch prey that might otherwise escape, but it is also vulnerable to impact. The study’s interpretation is that the thylacine’s unusually large skull provided structural support for this fast bite.

• The proposed prey and hunting style differ from the popular image. Researchers suggest thylacines may have ambushed small- to medium-sized marsupials, such as bandicoots, with a sudden strike rather than pursuing large animals over long distances. Earlier analysis of thylacine limb bones was also interpreted as more consistent with ambush hunting than endurance running. No wild thylacine hunt was filmed, so the hunting scene described in the video is a reconstruction, not a direct observation.

• The evidence weakens the “sheep killer” explanation for persecution. Thylacines were targeted by private and government bounty schemes. Their modest body mass and proposed bite mechanics seem poorly suited to bringing down healthy adult sheep, which were much larger. Researchers do not rule out attacks on vulnerable lambs, but argue that this would not explain claims of a widespread livestock threat. Other proposed causes of livestock losses include wild dogs, poor management, and theft.

• Genetic and developmental similarities may help explain the thylacine’s wolf-like outline. Research cited in the video found similarities between thylacine and dog DNA regions that regulate when genes are switched on and off during skull development. A 2021 study also reconstructed similar skull-growth paths in thylacines and wolves. The video emphasizes that similar developmental patterns do not mean the animals’ adult skulls functioned alike.

• Some anatomical questions remain unanswered. The thylacine’s infraorbital foramen—a passage associated in mammals with nerves supplying sensation to the upper lip and nose—was unusually large. This could indicate a sensitive muzzle, but the available evidence does not establish what passed through the opening or what it meant for the animal’s behavior.

• The thylacine’s history extends well before European arrival. Thylacines once lived on mainland Australia and persisted there until roughly 3,000 years ago. The reasons for their mainland disappearance remain uncertain; proposed factors include competition with dingoes, human activity, and climate change. A 2018 genome study reportedly found that genetic diversity had been declining long before European colonization, meaning the species was already vulnerable before bounty hunting intensified.

• De-extinction efforts raise scientific and cultural questions. Colossal Biosciences and the University of Melbourne’s Pask Lab are described as working toward a thylacine-like animal using edited cells from the fat-tailed dunnart, a small marsupial. The company has reported a near-complete thylacine genome and progress inducing ovulation in dunnarts. The video argues that resemblance alone would not capture the thylacine’s distinctive anatomy or behavior. It also raises questions about animal welfare, peer-reviewed publication, and the role of Aboriginal Tasmanian custodians in decisions about any resulting animal.

Methodology and evidence discussed

• Estimate body mass from scans of museum specimens.
• Compare three-dimensional skull scans and digital reconstructions across carnivorous mammals.
• Examine jaw shape and relate its geometry to bite speed, force, and structural stress.
• Combine skull evidence with earlier analyses of limb bones to infer likely hunting behavior.
• Reassess historical photographs and records, distinguishing documented evidence from disputed interpretations.
• Model possible extinction dates using 1,237 post-1910 records, each assigned a credibility rating.
• Use genome sequencing and developmental studies to investigate similarities between thylacines and other mammals.

Researchers, sources, and institutions featured

Researchers and historians

• Vera Weisbecker — Flinders University evolutionary biologist
• Douglas Rovinsky — paleobiologist involved in the 2020 body-mass study
• Borja Figueirido and Christine Janis — researchers cited for the 2011 limb-bone study
• Robert Paddle — thylacine historian
• Carol Freeman — researcher who studied the 1921 photograph’s glass negative
• Andrew Pask and Axel Newton — University of Melbourne researchers
• Barry Brook — University of Tasmania researcher who led the analysis of historical records

Institutions, companies, and cited publications

• Flinders University
• University of Melbourne and the Pask Lab
• University of Tasmania
• Colossal Biosciences
• Nature Communications — skull-comparison study
• Biology Letters — 2011 limb-bone study
• Communications Biology — 2021 skull-development study
• Nature Ecology & Evolution — 2018 genome study
• Science of the Total Environment — analysis of post-1910 thylacine records

Cultural sources mentioned

• Aboriginal Tasmanian communities and custodians, whose knowledge and names for the thylacine predate European accounts
• Palawa kani, the revived language of Tasmanian Aboriginal people; the video gives kaparunina as a thylacine name in that language