Field guide · Expert reference
The curated roster
1,274 guess identities; 1,236 profiles ready; 38 answer holds. Ready means the documented working tree and clue profile pass this catalogue’s conservative crowding check. Eligible profiles are selectable hidden answers in Expert mode. The original 36-genus sample retains separate puzzles and saved rounds.
Expert reference curated from the 9 October 2026 PBDB snapshot, reviewed primary literature and explicit close-relative diet inferences. Approved Expert reference; legal guesses and eligible answers remain distinct. The original sample is preserved separately.
Release decisions & open reviews
Troodon · answer identity
For daily answers, follow the 2025 Troodon genus concept or retain Stenonychosaurus as the canonical skeleton-based name?
Approved decision: Use the published 2025 Troodon framework. Troodon is the canonical hidden answer; Stenonychosaurus and Latenivenatrix remain legal equivalent winning guesses. Preserve all three source identities and fossil records separately. This is a chosen published framework, not universal consensus.
Diet of bird-like troodontid dinosaurs: synthesis of a contentious clade ↗
Dinevenator, a New Genus of Troodontid Dinosaur from the Late Cretaceous of New Mexico ↗
Alcovasaurus · answer identity
Keep Alcovasaurus as a separate daily-answer genus under the 2025/2026 Dacentrurus framework, or adopt Costa 2026 Miragaia and use Alcovasaurus only as a legal historical guess?
Approved decision: Retain Alcovasaurus as a legal guess, with an independent hidden-answer hold while the genus-level identity remains unresolved.
New genera outside the frozen baseline · Cryptarcus and Dinevenator
Refresh the captured PBDB baseline to assess newly described Cryptarcus and Dinevenator, or keep these outside this version until the next source refresh?
Approved decision: Wait for an explicit, verified PBDB baseline refresh before admitting Cryptarcus or Dinevenator. Capture source identities and specimen-specific mappings; do not invent IDs.
Alwalkeria · dinosaur scope
Keep the PBDB-selected guess while the revised name-bearing femur is Pan-Aves incertae sedis, or remove it from the dinosaur roster under the newer specimen-based treatment?
Approved decision: Exclude Alwalkeria from the dinosaur roster under the revised treatment of its name-bearing material. Preserve the source record and reconsideration condition.
Saltopus inclusion review
The dedicated revision places Saltopus outside Dinosauria. Retained as a provisional PBDB legal guess pending exclusion review; administrative root attachment is not dinosaur membership.
Approved decision: Exclude from the dinosaur roster.
Saltopus, a dinosauriform from the Upper Triassic of Scotland ↗
Protoavis inclusion review
Probably composite name-bearing material does not establish one diagnosable dinosaur genus. Retained guess; no independent hidden answer or unsupported finer ancestry.
Approved decision: Exclude unless an independently diagnostic name-bearing dinosaur identity can be supported.
A critical re-evaluation of the Late Triassic dinosaur taxa of North America ↗
Yaverlandia inclusion review
The 2026 dedicated revision leaves dinosaur identity unresolved; no supported maniraptoran, pachycephalosaur or other narrow branch.
Approved decision: Keep on hold; exclude from the active dinosaur roster pending secure identity.
A second specimen of the enigmatic Wealden reptile Yaverlandia ↗
Krzyzanowskisaurus inclusion review
Tooth-based identity may belong to Revueltosaurus or another non-dinosaurian archosaur; an ornithischian branch is unsupported.
Approved decision: Exclude pending secure dinosaur identity.
The first occurrence of the enigmatic archosaur Krzyzanowskisaurus hunti in Arizona ↗
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Ferganocephale inclusion review
Dubious tooth-based name; only a broad Saphornithischia interpretation is defensible, without a diagnosable independent hidden answer.
Approved decision: Exclude until diagnostic material supports this name.
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Gongbusaurus inclusion review
The dubious tooth-based type shiyii does not inherit the more informative ancestry of referred wucaiwanensis material.
Approved decision: Exclude the type-based genus pending diagnostic revision.
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Nanosaurus inclusion review
The dedicated 2025 revision finds the name-bearing material indeterminate; historical referred skeletons cannot establish an independent answer.
Approved decision: Exclude until a diagnostic name-bearing identity is supported.
A Review of Nanosaurus agilis Marsh and Other Small-Bodied Morrison Formation Ornithopods ↗
Stormbergia inclusion review
Chosen literature treats Stormbergia as a junior subjective synonym of Lesothosaurus; keep the PBDB guess distinct pending the inclusion decision.
Approved decision: Retain Stormbergia as an accepted equivalent of Lesothosaurus. It solves a hidden Lesothosaurus and records the canonical Lesothosaurus discovery; there is no separate Stormbergia answer.
A comprehensive phylogenetic analysis on early ornithischian evolution ↗
Serendipaceratops inclusion review
Fragmentary type and conflicting ceratopsian, ankylosaurian and indeterminate ornithischian interpretations support only Genasauria.
Approved decision: Retain as a broad Genasauria legal guess with an independent hidden-answer hold.
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Notoceratops inclusion review
Lost, fragmentary type and conflicting ceratopsian/hadrosaur interpretations do not support a dependable narrow working branch.
Approved decision: Retain as a broad Genasauria legal guess with an independent hidden-answer hold.
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
How clues stay fair
- PBDB defines captured guess identities, with individually sourced exceptions. Raw records, ages and fossil IDs remain immutable.
- Diet may be inferred from supported relatives. Each inferred profile states the basis and sources; ambiguous categories stay compatible.
- Use broad geological periods and positive geography. Qualified referrals, alternate horizons and incomplete ranges cannot become false exclusions.
- A locality clue selects an evidenced anchor. All recorded non-primary localities, qualified competitors and relevant missing metadata are included in comparisons.
- Free field reports start when six or more indistinguishable viable answers remain. They do not consume the player’s paid clue count.
- The fairness certificate assumes the standard clues are available and the direct branch has been reached; it does not prove an optimal fifteen-guess strategy from the root.
- The complete name/path scan uses referenced group rules; it is not 1,302 separate monographic revisions. Source access limits are preserved in the research handoffs.
- Hidden-answer holds are conservative evidence decisions, not claims that every held genus is invalid.
Find a genus
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Database exceptions
Saurornithoides · 69227
Use Saurornithoides Osborn 1924 (PBDB 38573), the troodontid genus treated in the published taxonomic review. Hold the same-name Nopcsa 1928 record (PBDB 69227) out of the expanded roster for nomenclatural review. This is an explicit identity selection, not a merger of records or their occurrence evidence.
Reconsider when: A source update resolves the recorded identity or scope problem.
Ancistrodon · 154360
PBDB 154360 is attributed to Huxley 1865 and placed directly under Dinosauria, but its only captured occurrence 434618 is Ancistrodon libycus from the Ypresian of Saudi Arabia. Priem treats that species name among fossil fish. Modern work treats Huxley’s Ankistrodon indicus as an Early Triassic proterosuchid archosauriform. The record appears to combine distinct historical names; the exact database repair is unresolved.
Reconsider when: A source update resolves the recorded identity or scope problem.
Priem 1914 · fossil fish discussion, Smithsonian translation ↗
Shuuvuia · 307772
Use only Shuvuuia (66043). Both PBDB spellings cite the same original description; primary systematic treatment and spelling-correction opinions support one genus. The user approved this explicit identity exception. Hold Shuuvuia (307772) out as a duplicate spelling identity, without transferring occurrence evidence or ancestry.
Reconsider when: A source update resolves the recorded identity or scope problem.
Hylosaurus · 66560
Use Hylaeosaurus (38822). The Hylosaurus record (66560) has the same Mantell 1833 attribution and original reference, no linked occurrences or child species, and a selected opinion explicitly marked misspelling. This is an approved spelling-identity hold; distinguish the database Mantell record from Fitzinger’s later Hylosaurus mantelli, treated as a nomen nudum by Raven. Preserve both records without transferring fossil evidence or ancestry.
Reconsider when: A source update resolves the recorded identity or scope problem.
Hoplosaurus · 53046
Retain Struthiosaurus (38830); hold Hoplosaurus Seeley 1881 (53046) out as a separate genus. The Dinosauria distribution chapter (2004) includes Hoplosaurus ischyrus within Struthiosaurus austriacus. PBDB still accepts Hoplosaurus and also attaches older Pelorosaurus synonymy opinions apparently involving a separate sauropod spelling usage. The full 2001 taxonomic reappraisal has not been inspected; do not assert a completed formal synonymy or database repair. This approved hold does not merge fossils, names or ancestry.
Reconsider when: A source update resolves the recorded identity or scope problem.
Weishampel et al. 2004 · Dinosaur distribution, Austrian Gosau entry ↗
Eosauropoda · 370667
PBDB 370667 self-accepts Eosauropoda Bonaparte 1986 at genus rank. The cited original publication instead treats Eosauropoda as a suprageneric grouping containing named genera. Exclude this rank-mismatched identity from guesses and answers. Preserve the source record; no genus, occurrence or ancestry transfer, and no new working-tree group is introduced.
Reconsider when: A source update resolves the recorded identity or scope problem.
Bonaparte 1986 · Smithsonian-hosted translation, pp. 38–39 and figure 65 ↗
Nemegtia · 68043
Use Nemegtomaia (95490) as the single dinosaur genus identity. Lü et al. 2005 formally replaced Nemegtia Lü et al. 2004 because that name was preoccupied by an ostracod. PBDB separately accepts the empty Nemegtia record (68043), but already links the original type occurrence to Nemegtomaia. Hold the former-name identity out of independent guesses and answers. Preserve all three canonical occurrences and the supported Nemegt and Baruungoyot profiles, including unresolved specimen-level horizon uncertainty. No occurrence transfer or ancestry amendment is introduced.
Reconsider when: A source update resolves the recorded identity or scope problem.
Lü et al. 2005 · formal replacement name ↗
Fanti, Currie & Badamgarav 2012 · both supported formations ↗
Captured identities and before/after locality checks · JSON ↗
Eucentrosaurus · 94334
Replacement name for the same nominal type species already represented by Centrosaurus; no independent answer animal.
Reconsider when: A source update resolves the recorded identity or scope problem.
Nessov1995. Dinosaurs of northern Eurasia. Smithsonian English translation. ↗
Proiguanodon · 383092
Original source uses this as a grouping within Iguanodon, not a separate described genus. It includes more than one later genus, so a single genus alias would be misleading.
Reconsider when: A source update resolves the recorded identity or scope problem.
Van den Broeck1900. Les dépôts à Iguanodons de Bernissart. MémSocBelgeGéol14:39–112. ↗
Proyandusaurus · 435994
Both publications expressly identify the same nominal Yandusaurus multidens species; this is not evidence for a second fossil animal.
Reconsider when: A source update resolves the recorded identity or scope problem.
Nectosaurus · 382945
This is the1910 dinosaur usage for Brown’s navajovius skull, not marine Nectosaurus Merriam1905. PBDB itself records the usage as a recombination of the accepted Kritosaurus navajovius species.
Reconsider when: A source update resolves the recorded identity or scope problem.
PBDB fresh species53196 identity/opinions snapshot retrieved2026-10-10. ↗
Galveosaurus · 67715
Both names denote the same holotype CLH-16. Galvesaurus is used by 2012/2019/2024 revisions and has the richer PBDB record, but priority dispute remains disclosed, not judicially resolved.
Reconsider when: A source update resolves the recorded identity or scope problem.
Sánchez-Hernández 2005, Galveosaurus herreroi, Zootaxa 1034:1–20 ↗
Sánchez-Hernández 2006, nomenclatural-priority discussion, Zootaxa 1201:63–68 ↗
Microsaurops · 83019
Published revision1991 treats it as a spelling/replacement artifact under Microcoelus, not an independently described animal.
Reconsider when: A source update resolves the recorded identity or scope problem.
Dachongosaurus · 313245
Explicit nomen nudum for Dachungosaurus, with Dachongosaurus alternative spelling. Revision states remains undescribed although an in-situ photograph was published. A photographed skeleton alone is not an independently diagnosed genus.
Reconsider when: A qualifying formal taxonomic publication that establishes an available name with differentiating characters and appropriate type-species fixation, or a demonstrated later validation. Additional locality or faunal-list mentions alone are insufficient.
Oshanosaurus · 313242
Explicit nomen nudum. Revision states remains undescribed and appears in a faunal list. No later formal validation found. Do not assume Eshanosaurus synonymy or automatically redirect.
Reconsider when: A qualifying formal taxonomic publication that establishes an available name with differentiating characters and appropriate type-species fixation, or a demonstrated later validation. Additional locality or faunal-list mentions alone are insufficient.
Damalasaurus · 313240
Explicit nomen nudum. Historical magnus/laticostalis usages do not establish available independently diagnosed genus. Zhao1983 p302 mentions Damalosaurus only as evolutionary example. Geographic disambiguation does not repair nomenclatural availability.
Reconsider when: A qualifying formal taxonomic publication that establishes an available name with differentiating characters and appropriate type-species fixation, or a demonstrated later validation. Additional locality or faunal-list mentions alone are insufficient.
Zhao1983. Phylogeny and evolutionary stages of Dinosauria. APP28:295-306. ↗
Microdontosaurus · 65648
Explicit nomen nudum. Zhao1983 p304 provides only a brief evolutionary example. Geographic and Chaya locality data do not establish nomenclatural availability.
Reconsider when: A qualifying formal taxonomic publication that establishes an available name with differentiating characters and appropriate type-species fixation, or a demonstrated later validation. Additional locality or faunal-list mentions alone are insufficient.
Zhao1983. Phylogeny and evolutionary stages of Dinosauria. APP28:295-306. ↗
Ponerosteus · 92286
Olshevsky 2000 naming-author statement calls the genus and species nomina dubia and doubtfully dinosaurian. A specimen which cannot securely establish even dinosaur affinity or an independently diagnosable genus is unsuitable as a separate playable genus.
Reconsider when: Published modern redescription establishes dinosaur affinity and diagnostic identity from the type or securely associated material.
Xuanhuasaurus · 313238
Zhao et al. 2006 p467 explicitly labels the earlier Xuanhuasaurus niei nomen dubium while stating no holotype, diagnosis or description was provided. Olshevsky 1991 p159 labels Xuanhuasaurus nomen nudum. An undescribed historical name for the material later formally described as Xuanhuaceratops; retained in the history, not counted as a separate playable genus.
Reconsider when: Original or later formal evidence establishes Xuanhuasaurus as an independently available and diagnostic genus, rather than this historical undescribed label.
International Code of Zoological Nomenclature, Article 13. Names published after 1930. ↗
Actiosaurus · 268200
Type reassessment calls the species inquirenda and identifies possible choristodere propodials, not a demonstrated dinosaur.
Reconsider when: A peer-reviewed type reassessment demonstrates dinosaur identity and diagnostic genus material.
Alwalkeria · 66343
2025 reassessment assigned the type-associated femur to Lagerpetidae and introduced Alickmeron; 2026 correction makes Alickmeron an objective junior synonym of Alwalkeria. Original assemblage is heterogeneous.
Reconsider when: Resolve latest type-based phylogenetic placement and apply dinosaur-scope policy. Never adopt Alickmeron as a second animal.
Avalonianus · 56608
The name-bearing tooth material is indeterminate archosaurian; historically associated postcranium does not diagnose this genus and relates to Camelotia.
Reconsider when: New peer-reviewed diagnostic name-bearing material establishes a defensible dinosaur genus.
Re-assessment of a large archosaur dentary from the Late Triassic of South Wales, United Kingdom ↗
Bagaraatan · 57248
The 2024 redescription partitions the original skeleton into a juvenile indeterminate tyrannosaurid type and caenagnathid hindlimb elements. Alleged diagnostic type features may be ontogenetic or individual variation; no supported automatic Tarbosaurus/Alioramus alias follows.
Reconsider when: Reconsider after a specimen-based rediagnosis or nomenclatural decision establishes a defensible independent genus. Preserve the original records; do not transfer the whole historical fossil assemblage.
Reassessment of the enigmatic Late Cretaceous theropod dinosaur Bagaraatan ostromi ↗
Changdusaurus · 65646
Historical Changtusaurus/Changdusaurus draft-name spellings; no formal genus description found.
Reconsider when: Locate a compliant formal description with type species.
Phylogeny and evolutionary stages of Dinosauria ↗
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Coloradia · 38639
Preoccupied by the moth genus; retained Coloradisaurus is the replacement.
Reconsider when: No independent slot; restore only if evidence establishes a different available dinosaur identity.
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Eugongbusaurus · 435996
The 1999 abstract proposes this new genus without a qualifying generic differential description or reference to one; unavailability is an Article 13.1 inference. Type fixation through monotypy is not the asserted defect.
Reconsider when: A compliant formal generic description, or demonstrate availability of the original act.
Fenestrosaurus · 65168
Informal preliminary name of Oviraptor, not an additional animal.
Reconsider when: A separate available genus with independently diagnostic material.
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Himeoolithus · 450385
Explicitly an egg oogenus, not an independently identified body genus.
Reconsider when: Change game scope to include egg taxa; a body-genus association alone would not create an independent animal.
Ingenia · 38560
Ingenia Barsbold 1981 is preoccupied by the nematode genus Ingenia Gerlach 1957; replacement Ajancingenia later becomes a subjective synonym of Heyuannia in the adopted revision.
Reconsider when: Reconsider after a specimen-based rediagnosis or nomenclatural decision establishes a defensible independent genus. Preserve the original records; do not transfer the whole historical fossil assemblage.
Oviraptorosaur anatomy, diversity and ecology in the Nemegt Basin ↗
Koutalisaurus · 91407
The supposed distinctive symphyseal projection on IPS 29920 was partly preparation infill. The 2013 revision identifies the cleaned dentary as indeterminate Lambeosaurinae and explicitly cannot refer it to Pararhabdodon. The 2021 Ajnabia matrix does not rebut this diagnostic failure.
Reconsider when: Reconsider after a specimen-based rediagnosis or nomenclatural decision establishes a defensible independent genus. Preserve the original records; do not transfer the whole historical fossil assemblage.
Ngexisaurus · 66640
Zhao lists this name but provides no qualifying individual diagnosis or type fixation; no subsequent formal description located.
Reconsider when: Locate a compliant formal description and type designation.
Ornithomimidorum · 66988
Provisional Latin grouping phrase, not an independently erected genus; B later became Betasuchus. Do not alias the entire A/B grouping to one genus.
Reconsider when: Demonstrate an available independent genus name and type species.
Abelisaurids before Abelisaurus: early reports of abelisaurid theropods from Europe ↗
Ovoraptor · 65172
Informal preliminary name of Velociraptor.
Reconsider when: A separate available genus with independently diagnostic material.
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Priodontosaurus · 105576
Catalogued incorrect spelling of Priodontognathus. Canonical genus is absent from current selected set; do not create an alias to a nonexistent game target.
Reconsider when: Correct source spelling/identity and explicitly approve canonical genus separately.
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Sangonghesaurus · 66638
Listed without a type species or qualifying original description. Do not infer synonymy with Tianchisaurus.
Reconsider when: Published compliant diagnosis, type species and independently identifiable material.
Phylogeny and evolutionary stages of Dinosauria ↗
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Sauraechmodon · 168391
Unused historical name for Echinodon, not an independently diagnosed animal. Exact nomenclatural availability need not be asserted for this duplicate-slot exclusion.
Reconsider when: Evidence for a separate available genus identity.
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Saurophaganax · 65370
The 2024 revision finds holotype OMNH 1123 unidentifiable as a diagnostic theropod and probably sauropod in morphology. Saurophaganax is not simply renamed Allosaurus anax; only particular formerly referred specimens support the new species.
Reconsider when: Reconsider after a specimen-based rediagnosis or nomenclatural decision establishes a defensible independent genus. Preserve the original records; do not transfer the whole historical fossil assemblage.
Sauropus · 67050
Footprint ichnogenus; revised type is indeterminate worn track material.
Reconsider when: Change game scope to include ichnotaxa.
The ichnogenus Atreipus and its significance for Triassic biostratigraphy ↗
Syntarsus · 38525
The dinosaur generic name is preoccupied by Syntarsus Fairmaire 1869. Unqualified Syntarsus is also ambiguous between rhodesiensis and kayentakatae. Do not redirect every Syntarsus guess to Megapnosaurus.
Reconsider when: Reconsider after a specimen-based rediagnosis or nomenclatural decision establishes a defensible independent genus. Preserve the original records; do not transfer the whole historical fossil assemblage.
Taxonomic notes on Megapnosaurus and 'Syntarsus' (Theropoda: Coelophysidae) ↗
Yezosaurus · 169801
Informal name for mosasaur MCM.M0009, described in 2008 as Taniwhasaurus mikasaensis and subsequently treated as Taniwhasaurus sp.; no independent dinosaur identity.
Reconsider when: Independently diagnostic dinosaur material and a validly established name.
A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia ↗
Saltopus · 38518
The dedicated revision places Saltopus outside Dinosauria.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
Saltopus, a dinosauriform from the Upper Triassic of Scotland ↗
Protoavis · 192928
Probably composite name-bearing material does not establish one diagnosable dinosaur genus.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
A critical re-evaluation of the Late Triassic dinosaur taxa of North America ↗
Yaverlandia · 38792
The 2026 dedicated revision leaves dinosaur identity unresolved; no supported maniraptoran, pachycephalosaur or other narrow branch.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
A second specimen of the enigmatic Wealden reptile Yaverlandia ↗
Krzyzanowskisaurus · 105061
Tooth-based identity may belong to Revueltosaurus or another non-dinosaurian archosaur; an ornithischian branch is unsupported.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
The first occurrence of the enigmatic archosaur Krzyzanowskisaurus hunti in Arizona ↗
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Ferganocephale · 64059
Dubious tooth-based name; only a broad Saphornithischia interpretation is defensible, without a diagnosable independent hidden answer.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Gongbusaurus · 38719
The dubious tooth-based type shiyii does not inherit the more informative ancestry of referred wucaiwanensis material.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
Fonseca et al. 2024: Supplementary Data 1, excluded and fragmentary taxa ↗
Nanosaurus · 38738
The dedicated 2025 revision finds the name-bearing material indeterminate; historical referred skeletons cannot establish an independent answer.
Reconsider when: Reconsider when diagnostic name-bearing material or a peer-reviewed revision supports a secure independent dinosaur genus within the published scope.
A Review of Nanosaurus agilis Marsh and Other Small-Bodied Morrison Formation Ornithopods ↗