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EXHIBIT 183

Patagonykus

Patagonykus puertai

Patagonykus is a Patagonian alvarezsaurid with a stout manual claw, powerful short forelimbs and an incomplete skeleton. [1]

Evidence profile

TWO WAYS TO PICTURE THE PAST

Compare the evidence with the familiar movie image. The illustrations are not to a shared scale.

01 / SKELETAL RECONSTRUCTION

A framework from the fossils

Patagonykus museum skeletal restoration, including a comparative skull and reconstructed missing body regions.

Patagonykus skeletal restoration photographed by Kabacchi in 2009; the licensed Flickr photograph is preserved on Commons. The known Patagonykus material lacks a skull, so the displayed complete head and much of the body are comparative restorations. The source supplies no fossil-versus-cast key or specimen number. This is not a complete original individual or a verified adult size reference. [1]

Patagonykus.jpg · Kabacchi. CC BY 2.0. Current licensed Commons image converted to WebP and proportionally reduced for the thumbnail, without upsampling. No additional cropping, mirroring, anatomical edits or compositing. Existing source restoration and scale annotations retained. CC BY 2.0 applies to these versions.

Skeletal mounts and drawings may restore missing parts; the caption identifies the displayed material.

02 / MOVIE-STYLE INTERPRETATION

A cinematic imagination

Illustrative reconstruction of Patagonykus puertai; missing anatomy, covering and colors are hypotheses.

Original cinematic interpretation of Patagonykus. Fragmentary postcranial fossils guide the short robust forelimbs. The head, missing hand details, complete body and covering remain comparative restorations. 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.

PERIODLate Cretaceous[4]
DIETCarnivoreEvidence and uncertainty in the dossier
TOTAL LENGTHSee the dossierEstimate scope matters
FOSSILS FOUNDArgentina[2]
CompareRead the dossierView the sources

MEET THE ANIMAL

Meet Patagonykus

Patagonykus belongs to a group of dinosaurs with unusually specialized arms and hands. Its fragmentary skeleton includes a stout main claw and a strongly developed projection at the elbow. These features help researchers recognize the animal and compare it with its relatives. The skull is missing, so a complete illustrated head is not something the fossils directly preserve. [D1]

Its diet is less certain than its impressive claw might suggest. Researchers have proposed animal feeding and insect eating for this broader group, using comparisons between skeletons. Direct intestinal evidence discussed in recent research belongs to Bannykus, a different dinosaur. A relative's preserved food cannot simply be treated as Patagonykus's own meal or proof of the same feeding specialization. [D5]

An additional finger fossil from Patagonia is more robust than the original specimen's. Its identification and rock-layer assignment remain qualified. That difference is interesting, but it cannot establish which individual was male or female, or how the animal changed as it grew. An isolated finger adds anatomical information without revealing a living social group. [D2]

PREHISTORIC ANIMAL DOSSIER

A life in profile.

The animal, the evidence, and the questions still open.

The known material establishes specialized hand anatomy, while skull shape and most feeding behavior remain comparative. Regression-based size estimates are model references rather than adult species ranges. [D1] [D4]

Profile scope: Genus — Patagonykus; P. puertai type MCF-PVPH 37, with separately qualified referral of manual digit MCF-PVPH 102. [D2]

Time
Late Cretaceous
Fossil locations in this exhibit
Argentina
How to read the evidence

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.

Body length

Inferred

About 3.29 m (regression reference)

Published Patagonykus model using Therrien–Henderson scaling. It restores a fragmentary animal; specimen maturity and a complete-body measurement were not independently recovered. [D4]

Body mass

Inferred

About 58 kg (appendicular regression)

Published 58.17 kg Patagonykus reference using Christiansen–Fariña equations. It is neither a population range nor an independently verified adult maximum. [D4]

Diet and feeding

Inferred

Animal feeding inferred; food unverified

Family-level carnivory and insectivory hypotheses rely on comparisons. Newly studied intestinal evidence belongs to Bannykus; it cannot establish Patagonykus prey or specialization. [D5]

Habitat and setting

Source supported

Portezuelo Formation, Patagonia

Turonian–Coniacian Neuquén, Argentina. The additional manual digit has imprecise provenance, so its formation referral remains provisional. [D4] [D2]

Movement

Inferred

Terrestrial biped inferred

Known hindlimb and vertebral anatomy support a two-legged reconstruction. No trackway or speed measurement documents how this individual moved. [D3]

Recognizable anatomy

Source supported

Stout main claw and enlarged olecranon

A hook-like process on manual phalanx I-1 distinguishes the hand. The fragmentary skeleton does not preserve a skull or a complete living outline. [D1]

Reproduction & life together

Reproduction and nesting

Not established

Not established here

Egg associations discussed for Bonapartenykus concern another genus. The inspected comparisons establish no Patagonykus eggs, nests or parent–young association. [D3]

Mating and courtship

Not established

Not established here

The referred manual digit is more robust than the type’s digit. Its qualified identification and limited sample cannot establish sex differences or mating behavior. [D2]

Social behavior

Not established

Not established here

An isolated, referred manual digit adds anatomy, not a group assemblage. Focused searches found no Patagonykus-specific evidence for cooperative or family behavior. [D2]

Dossier research & sources

Sources and inspection notes for the claims in this profile.

  1. Anatomy of Patagonykus puertai from the Late Cretaceous of Patagonia (Novas, 1997)Journal of Vertebrate Paleontology · Accessed 2026-10-02Original abstract inspected through publisher/author-indexed abstract, not full osteology. Fragmentary alvarezsaurid skeleton; compressed humerus, strong olecranon, distinctive manual phalanx I-1 and stout ungual. Original avialan nomenclature is historical; later research treats it within non-avian Alvarezsauria. · Inspected: abstract
  2. A new specimen of Patagonykus puertai from the Late Cretaceous of Patagonia (Chiappe and Coria, 2003)Ameghiniana 40(1), 119–122 · Accessed 2026-10-02Original four-page paper inspected. MCF-PVPH 102 is articulated manual digit I, referred Patagonykus sp. cf. P. puertai. It is more robust than the type MCF-PVPH 37, but the variation is not established as sexual or ontogenetic. Collection has imprecise stratigraphic provenance, provisionally Portezuelo Formation, northern Los Barriales. · Inspected: page
  3. New information on Bonapartenykus from the Allen Formation clarifies the Patagonykinae body plan (Meso et al., 2025)PLOS ONE · Accessed 2026-10-02Original full comparative sections inspected, including Patagonykus MCF-PVPH 37 vertebral, girdle and hindlimb anatomy. Patagonykus remains a distinct genus alongside Bonapartenykus. Bonapartenykus egg associations and new skeletal material are not transferred to Patagonykus. · Inspected: page
  4. Body size and evolutionary rate analyses reveal complex evolutionary history of Alvarezsauria (Meso et al., online 2024; issue 2025)Cladistics · Accessed 2026-10-02Original full methods, taxonomic sensitivity analysis and body-size results inspected. Appendicular regression equations estimate mass, and Therrien–Henderson scaling estimates length. Patagonykus is reported at 58.17 kg and 3.29 m. A separate sensitivity analysis assumes Nemegtonykus–Mononykus synonymy; this is evaluated against the distinct diagnoses in Lee 2019 and continued recognition in Averianov 2025. Supplement download returned an HTML challenge, so an individual Patagonykus row/maturity assessment was not independently recovered. · Inspected: page
  5. Direct evidence of carnivory in the early-diverging Alvarezsaurian Bannykus (Wang et al., 2025)The Innovation Geoscience · Accessed 2026-10-02Original publisher abstract and public summary inspected; dynamically loaded full article unavailable. Explicitly distinguishes morphological carnivory/insectivory hypotheses from the first direct intestinal evidence, which belongs to Bannykus. This source supplies the broader dietary uncertainty, not direct Patagonykus prey evidence. · Inspected: abstract

THE STORY IN THE FOSSILS

A hand that survives more completely than the head.

A second specimen preserves just the articulated main digit. Its increased robustness is interesting variation, but cannot be confidently converted into an adult size, sex or courtship claim. [2]

Comparative research keeps Patagonykus and Bonapartenykus separate. Their shared alvarezsaurid anatomy does not let another genus’s eggs become Patagonykus reproductive evidence. [3]

A note on scale and time

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 & editorial notes

Sources support the stated claims and scopes. Refer to the evidence notes for uncertainty.

  1. Anatomy of Patagonykus puertai from the Late Cretaceous of Patagonia (Novas, 1997)Journal of Vertebrate Paleontology · Accessed 2026-10-02Original abstract inspected through publisher/author-indexed abstract, not full osteology. Fragmentary alvarezsaurid skeleton; compressed humerus, strong olecranon, distinctive manual phalanx I-1 and stout ungual. Original avialan nomenclature is historical; later research treats it within non-avian Alvarezsauria. · Inspected: abstract
  2. A new specimen of Patagonykus puertai from the Late Cretaceous of Patagonia (Chiappe and Coria, 2003)Ameghiniana 40(1), 119–122 · Accessed 2026-10-02Original four-page paper inspected. MCF-PVPH 102 is articulated manual digit I, referred Patagonykus sp. cf. P. puertai. It is more robust than the type MCF-PVPH 37, but the variation is not established as sexual or ontogenetic. Collection has imprecise stratigraphic provenance, provisionally Portezuelo Formation, northern Los Barriales. · Inspected: page
  3. New information on Bonapartenykus from the Allen Formation clarifies the Patagonykinae body plan (Meso et al., 2025)PLOS ONE · Accessed 2026-10-02Original full comparative sections inspected, including Patagonykus MCF-PVPH 37 vertebral, girdle and hindlimb anatomy. Patagonykus remains a distinct genus alongside Bonapartenykus. Bonapartenykus egg associations and new skeletal material are not transferred to Patagonykus. · Inspected: page
  4. Body size and evolutionary rate analyses reveal complex evolutionary history of Alvarezsauria (Meso et al., online 2024; issue 2025)Cladistics · Accessed 2026-10-02Original full methods, taxonomic sensitivity analysis and body-size results inspected. Appendicular regression equations estimate mass, and Therrien–Henderson scaling estimates length. Patagonykus is reported at 58.17 kg and 3.29 m. A separate sensitivity analysis assumes Nemegtonykus–Mononykus synonymy; this is evaluated against the distinct diagnoses in Lee 2019 and continued recognition in Averianov 2025. Supplement download returned an HTML challenge, so an individual Patagonykus row/maturity assessment was not independently recovered. · Inspected: page
  5. Direct evidence of carnivory in the early-diverging Alvarezsaurian Bannykus (Wang et al., 2025)The Innovation Geoscience · Accessed 2026-10-02Original publisher abstract and public summary inspected; dynamically loaded full article unavailable. Explicitly distinguishes morphological carnivory/insectivory hypotheses from the first direct intestinal evidence, which belongs to Bannykus. This source supplies the broader dietary uncertainty, not direct Patagonykus prey evidence. · Inspected: abstract

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