Boreonykus certekorum comes from the Wapiti Formation of Alberta, about 73.3 million years ago. Its rare bones and teeth were found within the Pipestone Creek accumulation dominated by Pachyrhinosaurus. The association records a small predator in the same deposit, but not a preserved attack.
Quick facts
| Scientific name | Boreonykus certekorum Bell & Currie, 2016 |
|---|---|
| Group | Theropoda, Dromaeosauridae; subfamily uncertain |
| Age | Late Campanian, around 73.3 million years ago |
| Range | Wapiti Formation, Alberta, Canada |
| Holotype | TMP 1989.055.0047, an almost complete right frontal bone |
| Other material | A tail vertebra, hand claw, specialised foot claw and isolated teeth |
| Length | Often reconstructed around 1.5–2 m by comparison |
| Diet | Carnivorous, inferred from teeth and relationships |
From one skull-roof bone to a whole animal
A 52.4-millimetre right frontal preserves the distinctive angle and shape of its supratemporal crest.
A hand claw and enlarged second-toe claw fit a dromaeosaur, but neither touches the holotype.
Fourteen isolated teeth came from the horizon and cannot represent a single connected skeleton.
Sharing a deposit with Pachyrhinosaurus does not show whether the animal hunted, scavenged or arrived independently.
Discovery at Pipestone Creek
Phil Bell and Philip Currie described the material in a paper published online in 2015 and in the journal’s 2016 volume. The genus name means “northern claw”. The species name recognises support from Certek Heating Solutions and the Barendregt family.
The Pipestone Creek bonebed near Grande Prairie contains a dense accumulation of Pachyrhinosaurus lakustai. Years of excavation also recovered uncommon theropod remains. A predator might have fed on carcasses, lost teeth while feeding, or been incorporated into the layer through a separate event. None of those scenarios is proven by proximity alone.
The frontal and referred bones
The holotype is an almost complete right frontal, part of the skull roof above the orbit. Its supratemporal crest forms a low concave arc, and the paired crests would have met at an acute angle of about 55 degrees. The bone is relatively long and narrow, while the surface behind the crest is smooth and slopes backwards. This combination, not simply its small size, supports the diagnosis.
A distal tail vertebra, second-finger hand claw and enlarged second-toe foot claw were referred to the species. They do not overlap one another and match in scale, so they could represent one animal, yet they were not articulated with the frontal. Fourteen isolated teeth were also referred from the same horizon. Their assignment is weaker because shed dromaeosaur teeth can be similar and clearly represent multiple individuals.
The foot claw has a deep longitudinal groove and a developed flexor tubercle. It confirms the specialised raised second toe expected in dromaeosaurids. Its living keratin sheath is missing, and the familiar image of a knife-like slash is not a direct fossil observation. Biomechanical comparisons more strongly support gripping and restraining prey.
Classification and estimated size
The original analysis placed Boreonykus in Velociraptorinae, linking it with the branch that includes Velociraptor. Later matrices produced alternatives, including Dromaeosaurinae. This instability is expected when most of the skull and skeleton cannot be coded. The secure conclusion is a derived dromaeosaurid; the subfamily is unresolved.
Its frontal is close in size to that of Saurornitholestes. Reconstructions around 1.5–2 metres long are therefore comparative ranges, not measurements. No complete limb provides a direct body-length estimate, and no femoral circumference supports a robust mass calculation.
Northern habitat and unknown behaviour
The fossil layer lies in unit 3 of the Wapiti Formation and belongs to the late Campanian. Rivers, floodplains and wetlands formed a varied high-latitude environment that was much milder than modern Alberta. Small feathered predators occupied this ecosystem alongside ceratopsids and larger theropods.
No feather impression belongs to Boreonykus, but plumage is a strong inference from close maniraptoran relatives. No nest, egg, stomach content or pathology is known. Teeth support carnivory but not a list of prey, while the bonebed gives no evidence for packs or coordinated hunting.
Evidence and reconstruction
| Level | What belongs here |
|---|---|
| Direct | Frontal geometry and the anatomy of separately referred claws, vertebra and teeth |
| Supported inference | A small carnivorous dromaeosaur with feathers and a specialised second toe |
| Disputed | Subfamily and assignment of every isolated bone or tooth |
| Unknown | Exact size, colour, prey, social behaviour and cause of burial |
Frequently asked questions
Has a complete Boreonykus skeleton been found?
No. The holotype is one right frontal bone. A tail vertebra, a hand claw, a specialised foot claw and isolated teeth were referred separately.
Why does Boreonykus mean northern claw?
The name combines its northern Alberta locality with a Greek-derived word for claw, referring to the characteristic specialised claw of dromaeosaurids.
Did Boreonykus hunt Pachyrhinosaurus?
There is no direct evidence. Its remains occur in a Pachyrhinosaurus bonebed, but feeding, scavenging, transport and accidental burial are all possible explanations.
Was Boreonykus closely related to Velociraptor?
The original analysis placed it in Velociraptorinae, while later analyses recovered other positions including Dromaeosaurinae. Its exact subfamily remains uncertain.