EXHIBIT 121
Saurornitholestes langstoni
Saurornitholestes has a shorter, deeper skull than Velociraptor. [1]
TWO WAYS TO PICTURE THE PAST
Compare the evidence with the familiar movie image. The illustrations are not to a shared scale.
Saurornitholestes langstoni skull reconstruction by Gunnar Bivens, based on Currie and Evans’s anatomical study, principally UALVP55700. The scale bar belongs to the reconstruction. This is a schematic of interpreted anatomy, not a photograph of an intact skull; shaded contours and gaps should be checked against the original anatomical description. [1]
Saurornitholestes skull reconstruction.png · Gunnar Bivens. CC BY 3.0. Current Commons image converted to WebP and proportionally resized; no cropping, mirroring, anatomical edits or compositing. Original annotations retained. The source license applies to these versions.
Skeletal mounts and drawings may restore missing parts; the caption identifies the displayed material.
Original cinematic interpretation of Saurornitholestes langstoni. Colors, soft tissues, scenery and missing anatomy are reconstructed artistic choices; this is not a directly observed individual or behavior. Feathering and fine missing anatomy are comparative; no hunting or social behavior is portrayed. Lighting, coloration and scenery are artistic choices. This image does not document a fossil locality or behavior.
Original artwork · artistic interpretation.
Scientific view: source-informed reconstruction, credited paleoart or specimen-based imagery. Movie-style view: Original artistic interpretation. Reconstructions involve uncertainty.
MEET THE ANIMAL
Saurornitholestes langstoni has a shorter, deeper skull than Velociraptor, despite their familiar raptor resemblance. An unusual front tooth has been proposed as a tool for preening, or tending a body covering. That suggested function is not direct evidence of feathers in the studied fossil. Anatomical comparisons can make a familiar-looking dinosaur more distinct while leaving some details unresolved. [D1]
A 2026 conference report describes feeding traces on a Cryodrakon pterosaur bone, including an embedded Saurornitholestes tooth. This is evidence of feeding contact with that bone. It does not establish whether the dinosaur killed the pterosaur or fed on an animal already dead. The preliminary report supplies a concrete interaction without recording the whole sequence that produced it. [D6]
The genus also has a qualified New Mexican record. Saurornitholestes sullivani was named from one skull bone, but later authors questioned whether it belonged in the genus. That uncertainty should remain separate from the well-supported Alberta material. Shared names do not guarantee equivalent evidence: a nearly complete skeleton and a single referred bone answer different questions about the animals they represent. [D3] [D4]
PREHISTORIC ANIMAL DOSSIER
The animal, the evidence, and the questions still open.
A nearly complete Canadian skeleton improves its anatomy. A pterosaur bone with an embedded tooth provides feeding evidence, without showing how the pterosaur died. [D1] [D6]
Profile scope: Genus — Saurornitholestes; anatomical detail focuses on S. langstoni, with the questioned S. sullivani referral separated. [D4]
Source supported identifies a description documented by the cited source. Inferred marks a reconstruction or functional estimate. Debated marks competing interpretations. Not established means the sources reviewed for this dossier do not support a firm conclusion; it does not mean a behavior never occurred.
A size reference is an estimate, not a population range. Nesting evidence does not by itself establish courtship, mate choice, or lifelong pairing.
A little under 2 m (restored individual)
The 2019/2020 paper restores S. langstoni UALVP55700, including its missing tail tip. Histology describes it as almost mature and at least eight years old; this is not an adult maximum. [D2]
About 18 kg (limb-scaling model)
S. langstoni TMP1988.121.0039, from measured femoral circumference; maturity is unestablished, and this is not UALVP55700. [D7]
Direct pterosaur feeding contact
A conference redescription reports nine tibial traces and an embedded S. langstoni tooth in the Cryodrakon type. Feeding on the bone does not establish active predation rather than scavenging. [D6]
Dinosaur Park and qualified New Mexican records
S. langstoni is represented in Alberta. S. sullivani was named from a single frontal in New Mexico's Kirtland Formation; its generic assignment remains questioned. [D3] [D4]
Two-legged dromaeosaurid reconstruction
The near-complete skeleton supports hindlimb locomotion. The skull description does not establish a top speed or prove a particular sickle-claw attack sequence. [D2]
Shorter, deeper skull and unusual front tooth
Cranial differences distinguish it from Velociraptor. The proposed preening function of one premaxillary tooth is an interpretation, not direct proof of feathers in this fossil. [D1]
Not established here
Almost-mature histology in UALVP55700 does not identify sexual maturity. Focused searches did not establish an assigned egg clutch, nest or parental-care sequence. [D2]
Not established here
Reviewed skull/frontal studies do not document mate choice, pairing or a courtship ritual. No sex-specific display structure was securely established.
Not established here
Neither an embedded tooth nor an illustrated pair establishes cooperative hunting. Focused social searches found no secure genus-specific demonstration of a stable pack. [D6]
Sources and inspection notes for the claims in this profile.
THE STORY IN THE FOSSILS
A Saurornitholestes tooth lodged in a Cryodrakon bone anchors a rare feeding interaction. A 2026 conference abstract adds a detailed account of the traces, while the animal’s method of obtaining that food remains unresolved. [6]
UALVP55700’s restored length and TMP1988.121.0039’s modeled mass describe different individuals. [2] [7]
The dossier identifies the scope of each reference estimate. A mount, an individual fossil and a species-wide adult range are different measurements. Comparison metrics remain unavailable where adult scope has not been established. Unknown does not mean zero.
Sources support the stated claims and scopes. Refer to the evidence notes for uncertainty.
KEEP EXPLORING
Dromaeosaurus albertensis
Dromaeosaurus combines a robust skull with distinctive cutting teeth.
Tyrannosaurus rex
Tyrannosaurus rex was a large meat-eating dinosaur from the final part of the Cretaceous in western North America. Fossil teeth, bite marks and skeletons reveal a powerful animal whose behaviour still invites questions.
Velociraptor mongoliensis
Velociraptor mongoliensis was a lightly built meat-eater from Late Cretaceous Mongolia. Its long limbs, teeth and enlarged foot claws made it distinctive, while the Fighting Dinosaurs specimen records a remarkable interaction with a horned dinosaur.
