EXHIBIT 186
Falcarius utahensis
Falcarius combined long-clawed arms with unusual dentition. Utah’s abundant quarry material documents an early stage of therizinosaur dietary evolution. [1]
TWO WAYS TO PICTURE THE PAST
Compare the evidence with the familiar movie image. The illustrations are not to a shared scale.
Falcarius fossil block CEUM 8429 from Utah’s Cedar Mountain Formation, displayed in Price. The source identifies the genus but does not establish species, number of individuals or a living social group; it is not used to combine Crystal Geyser and Suarez Site evidence. [3]
Falcarius fossil block CEUM 8429 · Jens Lallensack. CC BY-SA 4.0. Converted to WebP and resized proportionally within verified native dimensions; no anatomical edits. Existing Commons crops or figure revisions are retained under the inspected file license.
The photograph or figure shows the credited fossil material; displayed mounts and labels can include interpretation.
Original cinematic interpretation of Falcarius utahensis. Primitive proportions and three-clawed hands differ from the later giant therizinosaurs. The tooth-bearing front jaw has a closed rounded snout; filamentous covering and missing soft tissues remain comparative choices. Lighting, colors and scenery are artistic choices; this image does not document directly observed behavior. 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
Falcarius helps show how some relatives of meat-eating dinosaurs became adapted to plant food. Its skeleton combines older features with changes associated with herbivory. That makes it interesting as an evolutionary transition, although the bones do not prove that it ate only plants. The original four-metre restoration combines evidence rather than measuring one complete adult skeleton. [D1]
Imagine a two-legged dinosaur with long arms and curved claws. Museum reconstructions sometimes give it a downy covering, based on feathers preserved in related therizinosaurs. Those feathers are a comparative interpretation for Falcarius, rather than plumage found on its own skeleton. Its familiar illustrated appearance therefore brings together direct skeletal evidence and ideas drawn from relatives. [D4]
The Crystal Geyser quarry contains remains from many individuals, including skull and jaw material. Large front teeth are part of this animal's distinctive feeding equipment. Researchers have considered whether the accumulation records a social gathering. Finding many bones together raises that question, but it does not automatically establish a herd, a breeding colony or the cause of every animal's death. [D3]
PREHISTORIC ANIMAL DOSSIER
The animal, the evidence, and the questions still open.
Large front dentary teeth contrast with the smaller teeth behind them. The quarry’s many bones supply a composite anatomical picture, rather than one intact four-metre animal. [D3]
Profile scope: Genus profile includes F. utahensis at Crystal Geyser and the September 2026 transfer F. suarezarum from the Suarez Site. Their measurements and depositional histories remain separate. [D2]
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.
About 4 m; F. utahensis composite restoration
The 2005 reconstruction combined material from several individuals. Its length is a restored reference, not one measured adult, an adult maximum or a size estimate for F. suarezarum. [D1]
About 128 kg; largest reviewed quarry-femur model
The 2012 study models a 403 mm femur, UMNH 13423, from Crystal Geyser at 127.7 kg using femoral length. Independent adult maturity is not established; this is not a genus-wide maximum. [D5]
Plant feeding inferred from transitional anatomy
The original account interprets anatomical changes toward herbivory, while retaining primitive feeding features. Exact plants, animal-food intake and obligate herbivory are not demonstrated by a preserved meal. [D1]
Lower Yellow Cat Member, Utah; exact age uncertain
The 2026 revision recognizes distinct Crystal Geyser and Suarez horizons. Lower Yellow Cat age estimates span possible Berriasian–Aptian assignments; unreliable or reworked dates prevent a precise local age. [D2]
Bipedal body; grasping hands
Museum anatomy depicts walking on the hindlimbs with long arms and manual claws. Downy covering is a comparison with other therizinosaurs, not preserved Falcarius plumage. [D4]
Enlarged anterior dentary teeth
New F. utahensis jaws preserve large incisiform teeth near the front and different teeth posteriorly. A toothless hooked lower beak would conceal or contradict that documented front dentition. [D3]
Not established here
Focused searches found no securely identified Falcarius eggs, nests or parental care. The quarry’s multiple individuals do not identify a breeding colony or nest producer. [D3]
Not established here
Focused searches did not establish sexes, mate choice, mating seasons or a particular courtship display. Restored colors and feather arrangements are artistic interpretations.
Social aggregation proposed for Crystal Geyser
The cranial study interprets a population mass mortality and possible social aggregation. Separate REE signatures in three units and an unresolved death mechanism prevent treating every bone as one observed herd. [D3] [D6]
Sources and inspection notes for the claims in this profile.
THE STORY IN THE FOSSILS
A new September 2026 analysis places the former Geminiraptor suarezarum in Falcarius. Its CEUM 73719 maxilla and Suarez locality are distinct from the F. utahensis type braincase and Crystal Geyser body material. [2]
Chemical signatures distinguish three quarry depositional units. That evidence helps test how bones accumulated, but does not directly reveal mate choice, family membership or synchronized group behavior. [6]
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
Acrocanthosaurus
This Early Cretaceous carnivore is known from North American fossils. Its high vertebral spines give it a distinctive raised back profile.
Baryonyx
Baryonyx had a crocodile-like snout and an enlarged hand claw. Its preserved last meal supports a carnivorous diet that included more than fish.
Suchomimus
This Niger spinosaur was closely similar to Baryonyx. Its hooked, rounded teeth suggest a role catching fish in ancient river environments.
