EXHIBIT 81
Lesothosaurus diagnosticus
Lesothosaurus was a small early ornithischian.
TWO WAYS TO PICTURE THE PAST
Compare the evidence with the familiar movie image. The illustrations are not to a shared scale.
Skull display identified as Lesothosaurus diagnosticus at the Royal Belgian Institute of Natural Sciences, photographed by Esv. The Commons revision by Conty removed the background and aligned separated pieces; an outline depicts missing muzzle anatomy. Display and digital assembly do not establish an undistorted living skull; an inventory number is not supplied. [4]
Lesothosaurus.JPG · Esv; edited by Conty. CC BY-SA 3.0. Current 1120px Commons file converted to WebP and resized proportionally for the thumbnail; no new anatomical edits. Source already includes background removal and piece alignment. Same source license applies.
The photograph or figure shows the credited fossil material; displayed mounts and labels can include interpretation.
Original cinematic interpretation of Lesothosaurus diagnosticus. Coloration, soft tissues and scenery are artistic choices; reconstructed proportions do not establish a measured individual. 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
Lesothosaurus was a small, two-legged dinosaur from Early Jurassic southern Africa. A museum reference of about one metre gives a simple picture of its scale, but larger individuals are known. Size by itself cannot identify a fully grown adult. That matters when comparing fossils that may represent different stages of the same animal's growth. [D1] [D2]
CT-based work reconstructs a small skull with large eye openings and toothed jaws. The fossils are incomplete or distorted, so a restored head combines preserved pieces with interpretation. A complete picture can make the anatomy easier to understand while still showing more than any one fossil actually retains. [D4]
Its teeth have also been tested using different dietary models. The models do not agree completely, and researchers favor a diet mainly of soft plant material with possible occasional animal food. This is an inference about feeding, not a preserved menu. Lesothosaurus shows how scientific uncertainty can be specific: the evidence can support a plant-dominated diet without proving that the animal never ate anything else. [D5]
PREHISTORIC ANIMAL DOSSIER
The animal, the evidence, and the questions still open.
Diet and aggregation remain inferred.
Profile scope: Species — Lesothosaurus diagnosticus; growth stages require care.
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 1 m (museum reference); larger individuals known
The museum’s rounded reference has no life-stage basis. Growth research includes larger, older individuals still lacking proof of complete growth; one metre is not an adult maximum. [D1] [D2]
About 6.3 kg for NHMUK RU B17
Limb-circumference estimate; full maturity is not independently established. This is not a normal adult mass. [D6]
Mainly plants; occasional omnivory possible
A comparative dental study classifies Lesothosaurus differently with its two models. The authors favor predominantly soft plant matter with possible occasional animal food; exact meals are not preserved. [D5]
Upper Elliot Formation, southern Africa
Jaw material and geological discussion place the species in continental deposits of Lesotho and South Africa. Increasing aridity is regional context, not proof of one preferred microhabitat. [D3]
Two-legged movement
The museum describes a small biped. This does not establish a maximum running speed or the posture of every growth stage. [D1]
Small skull, large eye openings and toothed jaws
CT-based descriptions recover cranial anatomy from incomplete and distorted fossils. The assembled scientific image remains a display; missing structures and living soft tissues require reconstruction. [D4]
Possible reproductive maturity around 2–4 years
Growth slowing at these estimated ages is interpreted as possible reproductive maturity. It is not direct evidence of egg laying, and reviewed sources do not establish nests, incubation or parental feeding. [D2]
Not established here
The reviewed jaws, tooth mechanics, growth and taphonomy studies do not establish pairing, mating displays or sex-specific ornaments.
Mixed-age aggregations proposed
A single-species bonebed and histology support a group containing different growth stages. The authors infer aggregation; duration, herd structure and social roles remain unestablished. [D2]
Sources and inspection notes for the claims in this profile.
THE STORY IN THE FOSSILS
Its teeth do not settle every dietary question. Shape-based and mechanical models disagree between herbivory and omnivory. This leaves a plausible plant-dominated diet while keeping occasional animal food as a possibility. [5]
CT scans of an adult lower jaw reveal how replacement teeth formed at different positions. Research also discusses whether larger fossils once named Stormbergia represent growth stages of Lesothosaurus rather than a distinct animal. [3]
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
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Massospondylus was a southern African sauropodomorph with a long neck and a prominent thumb claw. Preserved eggs, embryos and nesting grounds illuminate reproduction while young-animal posture remains debated.
Heterodontosaurus tucki
Heterodontosaurus was a small southern African ornithischian with contrasting tooth types. Its tusk-like teeth, chewing adaptations and unusual chest anatomy open different windows onto its biology.
Scutellosaurus lawleri
Scutellosaurus paired small bony armor with a lightly built body and predominantly bipedal movement.
