Field guide · Complete research decisions · 10 October 2026

What we changed, and why

Historical v10 checkpoint. Later inclusion decisions and the current roster desk supersede the earlier retained-guess statuses.

All 30 remaining locality proposals have been reviewed. 18 now fall below five in every tested state; 12 still have five-plus states. These are catalogue diagnostics, not approved fossil-absence filters or daily answers.

Six explicit identity holds leave 1,308 expansion candidates. The live game remains the 36-genus sample.

The identity exceptions

Eucentrosaurus

Replacement name for the same nominal type species already represented by Centrosaurus; no independent answer animal.

Original1989 naming page unavailable; identity corroborated in two primary scholarly revisions. Do not claim a specific ICZN conservation ruling or settle authority-date discrepancy beyond verified evidence.

Olshevsky1991. A revision of the parainfraclass Archosauria Cope1869, excluding advanced Crocodylia. MesozoicMeanderings2.

Nessov1995. Dinosaurs of northern Eurasia. Smithsonian English translation.

Proiguanodon

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.

Do not assign Bernissart because it occurs in the paper title. No one canonical target: constituent species are now associated with Cumnoria52998 and Barilium167439; these modern mappings are context, not an implemented alias.

Van den Broeck1900. Les dépôts à Iguanodons de Bernissart. MémSocBelgeGéol14:39–112.

Proyandusaurus

Both publications expressly identify the same nominal Yandusaurus multidens species; this is not evidence for a second fossil animal.

2005 full original not obtained; same-species naming statement is explicit in the primary abstract. No locality transfer needed for a held duplicate.

Knoll1999. The family Fabrosauridae. IV European Workshop on Vertebrate Palaeontology, Programme and Abstracts, p65.

Barrett, Butler & Knoll2005. Small-bodied ornithischian dinosaurs from the Middle Jurassic of Sichuan, China. JVP25:823–834.

Nectosaurus

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.

Brown1910 full original not obtained in this bounded run. Correct original Versluys dinosaur usage was read, and exact identity bridge comes from fresh PBDB species opinions rather than secondary genus lists. Do not merge into the marine reptile genus or claim publication-priority details not independently established.

Versluys1910. Streptostylie bei Dinosauriern, nebst Bemerkungen über die Verwandtschaft der Vögel und Dinosaurier. ZoolJahrbAnat30:175–260.

PBDB fresh species53196 identity/opinions snapshot retrieved2026-10-10.

Galveosaurus
Microsaurops

Published revision1991 treats it as a spelling/replacement artifact under Microcoelus, not an independently described animal.

Original Kuhn entry not read; PBDB1964 versus revision1963 discrepancy disclosed. No formal Saltasaurus synonym asserted and no new genus or tree forced.

Olshevsky 1991, A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia, p.145

Chure and McIntosh 1989, A bibliography of the Dinosauria (exclusive of the Aves), Annals of the Carnegie Museum

Kuhn 1964, Ungelöste Probleme der Stammesgeschichte der Amphibien und Reptilien, Jahreshefte des Vereins für vaterländische Naturkunde in Württemberg 118/119:293–325

Proposed aliases are deferred to the expanded input registry. No fossil evidence is transferred.

Exact occurrence amendments

Genus / occurrenceChangeTreatment
Daxiatitan · 829375formation: Upper → blankcorrect
Yongjinglong · 1587594formation: 5 → blankcorrect
Lingwulong · 1412529formation: blank → Yanancorrect
Ganzhousaurus · 1126121formation: blank → Nanxiongcorrect
Jiangxisaurus · 1163955formation: blank → Nanxiongcorrect
Nankangia · 1183820formation: blank → Nanxiongcorrect
Pellegrinisaurus · 508143formation: Allen → Anacleto; member: Lower → blank; geological_group: Malargüe → blank; qualified: blank → Trueretain alternative

All 30 proposal outcomes

Remaining candidates after tested wrong guesses. The current anchor is the best already supported alternative; smaller counts still need scientific eligibility review.

TargetBeforeAfterCurrent anchor
Equijubus4–63–4Gansu · CN
Gongpoquansaurus4–63–4Gansu · CN
Abrosaurus4–54–5Shaximiao Formation · CN
Bisticeratops4–64–6Kirtland Formation · US
Navajoceratops4–64–6Kirtland Formation · US
Terminocavus4–64–6Kirtland Formation · US
Yeneen4–74–7Bajo de la Carpa Formation · AR
Yunmenglong4–102–4Henan · CN
Daliansaurus3–63–6Yixian Formation · CN
Sinusonasus3–63–6Yixian Formation · CN
Pellegrinisaurus3–61–2Anacleto Formation · AR
Wendiceratops3–63–6Oldman Formation · CA
Chinshakiangosaurus6–93–4Fengjiahe Formation · CN
Damalasaurus6–365–34Daye Group · CN
Isanosaurus4–51–1Nam Phong Formation · TH
Kotasaurus4–61–2Kota Formation · IN
Lamplughsaura4–51–1Dharmaram Formation · IN
Microdontosaurus6–365–34Chaya Group · CN
Sanpasaurus6–93–4Ziliujing Formation · CN
Datousaurus7–125–10Shaximiao Formation · CN
Shunosaurus7–125–10Shaximiao Formation · CN
Agilisaurus3–123–4Shaximiao Formation · CN
Hexinlusaurus3–123–4Shaximiao Formation · CN
Pulaosaurus1–101–2Tiaojishan Formation · CN
Sanxiasaurus1–101–2Xintiangou Formation · CN
Yandusaurus3–123–4Shaximiao Formation · CN
Caudipteryx5–93–4Jianshangou Member · Yixian Formation · CN
Ningyuansaurus5–93–4Yixian Formation · Jianchang · Liaoning · CN
Protarchaeopteryx5–93–4Jianshangou Member · Yixian Formation · CN
Istiorachis2–61–3Wessex Formation · UK

Decisions for every shared case

Each entry states the decision, remaining uncertainty and exactly how its sources were accessed.

Gansu hadrosauroids

Use broad Gansu clue after adding Koutalisaurus’s Spanish profile and holding the Nectosaurus duplicate. Retain the four documented Gansu genera; no exclusive quarry filter.

Still uncertain: The published Spanish type does not certify exhaustive range absence; Expert facts and tree still require validation.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Shaximiao mamenchisaurids

Refine confirmed Lower/Upper occurrences; retain the Qijianglong conflict and genus-wide Omeisaurus range. Do not pretend five names establish five independent animals.

Still uncertain: Qijianglong has contradictory 2025 literature and unpublished remapping. Zigongosaurus identity is disputed; no raw occurrence is present in the frozen catalogue. Its Upper Shaximiao assertion is a historical literature mapping. Do not force Shunosaurus or any broad genus into one member solely from a review’s assemblage label.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Kirtland chasmosaurines

Retain qualified Fruitland/Kirtland identities and Naashoibito’s alternative naming schemes; use member information without erasing unknown or referred material.

Still uncertain: Titanoceratops type locality and genus interpretation remain uncertain. Torosaurus exact specimen identity behind proxy occurrence is not verified; no claim that the 2025 main paper confirms that row. Different formation schemes for Naashoibito are a legitimate stratigraphic convention difference.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Bajo de la Carpa titanosaurs

Keep the seven-genus formation overlap; use recorded locality positives carefully and free help for genuine residual overlap. Do not turn an area inventory into an exclusive occurrence whitelist.

Still uncertain: Full Yeneen inventory not obtained; published indexed metadata and firsthand institutional author account distinguish this limitation. Cerro Overo–La Invernada contains unidentified titanosaurs; three currently named local genera does not prove all other genera absent. Neuquensaurus type/old strata correlations and its referred material need specimen-specific treatment, not a genus-wide deletion.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Jiangxi somphospondylans

Bind Hekou summaries to the Gansu source rows, clear Upper/5 as false formation names, and keep the Adamantisaurus Brazilian supplement. Preserve Jiangxi matches without adding phantom unknown-province fossils.

Still uncertain: Hekou remains a group; no invented formation or geological equivalence.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Jinhua somphospondylans

Keep Jinhua/Zhejiang profiles and the early Late Cretaceous literature interpretation. Flag Chinese Erketu as an unconfirmed affinity-based referral, retaining it conservatively.

Still uncertain: Do not infer genus absence or force tree placement; Fangyan-to-Jinhua revision is specimen-specific.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Xinlong somphospondylans

Adopt the explicitly sourced Xinlong/Napai/Napan regional naming relationship. Keep Liubangosaurus and Fusuisaurus together at Liubang.

Still uncertain: A shared quarry does not produce a unique answer; all wider referrals remain.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Haoling somphospondylans

Keep Haoling/Henan/Ruyang as a supported broad clue for Yunmenglong, Ruyangosaurus and Xianshanosaurus. Repair comparison metadata; reject an exclusive quarry subdivision without specimen inventories.

Still uncertain: Full Haoling material inventory was not obtained; county/type-site exclusivity is unproved. Do not approve an answer from the smaller catalogue count.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Yixian troodontids

Retain the real five-genus Lujiatun assemblage; separate Baicai Gou positively without assigning Jianianhualong to Lujiatun or promising member clues always solve the crowding.

Still uncertain: Several fossils were commercially/farmer collected; locality certainty cannot be improved by inventing quarry precision. Do not transfer the older Jinzhousaurus age estimate to all Jianianhualong/Yixian specimens. Formation/member overlap is genuine; precise phylogenetic probes and verified diagnostic hints may still differentiate some states.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Allen lithostrotians / Pellegrinisaurus

Treat Anacleto as the preferred published interpretation of the exact type quarry, while retaining a qualified Allen alternative and avoiding an exclusive formation clue.

Still uncertain: A 2017 meeting abstract proposed return to Allen; Cerda 2021 rejected its unpublished status at that time. The later Anacleto assemblage paper still explicitly says exact position uncertain. No later specimen-specific formal Allen remapping was located in the bounded search.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Oldman centrosaurines

Keep recent Avaceratops CMN 8804 referral, qualify lost-quarry Spinops alternatives, and use Wendiceratops lower Oldman type horizon positively without deleting historical or unknown comparative occurrences.

Still uncertain: Avaceratops CMN 8804 is a genus-level referral, not confirmation of the type species. Spinops quarry provenance remains genuinely uncertain. Historical Monoclonius nomenclature and referrals are reviewed by a separate identity workstream; this review does not overrule PBDB inclusion.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Fengjiahe basal sauropods

Retain Chinshakiangosaurus Fengjiahe/Yunnan. Add Lower Lufeng/Yunnan profiles for Dachongosaurus and Oshanosaurus, hold Microsaurops as an identity artifact, and preserve the earlier Eosauropoda rank hold.

Still uncertain: Original draft-name accounts remain unverified; those genera remain valid guesses under PBDB policy, with hidden-answer readiness pending.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Daye / Damalasaurus

Retain Damalasaurus with Daye group and the captured Duogaila member; normalize the administrative Xizang label. Prefer supported province/context clues rather than inventing a Daye Formation.

Still uncertain: Original naming account and modern unit hierarchy remain unverified; not hidden-answer ready.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Nam Phong / Isanosaurus

Keep the Thai Nam Phong footprint. Treat current age evidence as Jurassic with Early Jurassic favored, explicitly qualified; do not use the original Triassic date as a hard eliminator.

Still uncertain: Later juvenile sites or dates do not automatically apply to the Isanosaurus type. Runtime age facts were not overwritten.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Kota / Kotasaurus

Use broad Kota/India locality context for Kotasaurus and Barapasaurus; record positive type quarries without treating them as exclusive. Keep Barapasaurus material at Krishnapur as well.

Still uncertain: Early–Middle Jurassic dating and a complete referral inventory remain separate from game eligibility.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Dharmaram / Lamplughsaura

Keep Lamplughsaura in Upper Dharmaram/India with conservative Early Jurassic context. Retain Pradhania in the same unit; do not invent a unique site clue.

Still uncertain: Sinemurian/Hettangian correlation uncertainty remains; no exact age override.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Chaya / Microdontosaurus

Retain Microdontosaurus’s captured Chaya group and Dabuka/Daye locality. Normalize Xizang administrative spelling; do not convert Chaya Group to an invented Dapuka Formation.

Still uncertain: Original naming, specimen identity and modern hierarchy unavailable. Retain guess inclusion; withhold hidden-answer readiness.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Ziliujing / Sanpasaurus

Keep Sanpasaurus’s documented Maanshan/Ziliujing locality. Restrict modern positive literature referrals to IVPP V156 under the 2016 revision; flag older comparison records rather than deleting unmatched raw rows.

Still uncertain: The captured proxy rows do not identify individual specimens; rejected V221/V222/V715 cannot be assigned to an occurrence solely by locality.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Shaximiao eusauropods

Use honest member/site information where known; shared Lower Shaximiao quarries are genuine overlap and require free help if they remain an indistinguishable five-plus state.

Still uncertain: Exact site absence is not established by a list of type localities. Dating and phylogenetic assignments require separate reviews; old assemblage labels do not settle every taxon’s age or branch.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Zhanghe / Nebulasaurus

Retain Nebulasaurus’s Zhanghe/Yunnan footprint and all known comparison occurrences; shared missing profiles have now been addressed where evidence supports them.

Still uncertain: Catalogue improvement is not proof of a unique quarry or exhaustive range.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Shaximiao small ornithischians

Hold Eucentrosaurus, Nectosaurus, Proiguanodon and Proyandusaurus as nonindependent identities. Add Paulodon, Koutalisaurus, Hanssuesia and Ponerosteus positive profiles; retain Xuanhuasaurus unresolved.

Still uncertain: Hanssuesia scientific synonymy remains debated; exclude rejected Two Medicine literature referrals. Xuanhuasaurus original/type bridge unavailable.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Tiaojishan / Pulaosaurus

Keep Pulaosaurus Tiaojishan/Hebei/Qinglong positive locality. Address unrelated missing historical profiles; do not invent a narrower exclusive site to compensate for them.

Still uncertain: Standard diet/date/tree evidence remains subject to separate Expert eligibility checks.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Xintiangou / Sanxiasaurus

Keep Sanxiasaurus Xintiangou/Yunyang/Chongqing from the original abstract and frozen row. Repair shared historical profiles; retain every documented comparison occurrence.

Still uncertain: Full original material inventory was not obtained; do not claim exhaustive referrals or exclusive site separation.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Yixian oviraptorosaurs

Complete exact Nanxiong formation assignments for Ganzhousaurus, Jiangxisaurus and Nankangia, and preserve Banji’s possible provenance. Bind summaries to existing Jiangxi rows. Keep the genuine northern Yixian assemblage.

Still uncertain: Banji remains uncertain; commercial provenance does not support a precise quarry. Free assistance is needed only for actual residual indistinguishability.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Miaogou / Yuanyanglong

Keep Yuanyanglong Miaogou/Inner Mongolia; apply southern comparison-profile repairs and the previously approved Nemegtia replacement hold. No narrower artificial quarry clue.

Still uncertain: Original full description was not obtained in this follow-up; no exclusive whole-genus footprint certified.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

Wessex / Istiorachis

Use broad Wessex after adding the Spanish Paulodon/Koutalisaurus profiles and holding duplicate Nectosaurus. Record Istiorachis’s Black Band discovery positively, without requiring a quarry clue.

Still uncertain: The Black Band also preserves other dinosaurs; it is not an exclusive whole-genus range. Current full Wiley locality text was read.

Answer readiness: pending reviewed Expert tree, standard facts and complete comparison footprints

When free help is needed

Current policy: allow five remaining indistinguishable answers. Provide a free distinguishing clue at six or more when informative available tree probes and standard clues cannot separate them; the support should leave at most five. A formation count alone is not the trigger. The five-candidate-limit review assesses every chosen locality comparison and distinguishes supported target routes from uncertain hypothetical outcomes. New expanded-roster runtime clues are not activated.

What remains open

The full current screen retains 17 crowded pool targets, including 5 outside this original queue. All are in the JSON.