Extinct Sahul Fauna Catalog

Summary

A structured catalog of major extinct Sahul fauna, with ecological role, body size, and constraint implications for each. Entries are tiered by temporal confidence for the ~2 MYA representative window: lineage-level pressures with near-certain presence, later-Pleistocene named species that are valid constraint analogues but not confirmed at ~2 MYA, and excluded taxa.

Metadata

Primary topic: Extinct Sahul fauna catalog
Layer: Real-world reference
Topics: megafauna, extinct species, catalog, diprotodontids, Zygomaturus, Palorchestes, thylacoleonids, Megalania, Quinkana, thylacine, dromornithids, Zaglossus, Sahul, early Pleistocene
Real-world period: Early Pleistocene
Real-world anchor: ~2 MYA
Reference window: representative glacial maximum
Regions: Sahul (Australia, New Guinea)

Core Reality

Entries are organised by confidence tier for the ~2 MYA window. The constraints each lineage imposes are real regardless of whether the exact named species is confirmed at ~2 MYA; the tiers control which specific taxon names are safe to use.

Tier 1 — Near-2 MYA confirmed or well-supported

Taxa where the lineage or genus has documented presence in the relevant early Pleistocene window.

Diprotodontid lineage (diprotodontid-grade megaherbivores — the family Diprotodontidae persisted through this window)

Body mass range across the lineage: several hundred to over 1,000 kg.
Ecology: large marsupial browsers and browser-grazers on woody vegetation, shrubs, and chenopod plants. Waterhole dependent with evidence of seasonal movement.
Constraint: diprotodontid-grade browsing pressure on vegetation and permanent waterhole dependence are secure baseline facts for ~2 MYA Sahul. The specific genus or species cannot be asserted without further resolution. See Tier 3 for Diprotodon optatum as a later analogue.

Zygomaturine lineage (zygomaturines — semi-aquatic marsupial browsers within the diprotodontid family)

Body mass range: 200–700 kg.
Ecology: associated with wetland and floodplain margins; likely grazed or rooted in aquatic and semi-aquatic vegetation.
Constraint: specialised to wetland and riparian zones; presence requires productive wet margins and does not indicate dryland grazing capacity.

Palorchestid lineage (palorchestids — large clawed marsupial browsers; lineage from Miocene through Pleistocene)

Body mass: several hundred kg for larger representatives.
Ecology: retractile claws indicate specialist browsing on specific vegetation types, possibly bark-stripping, root-digging, or branch-pulling. Not a grazer.
Constraint: clawed manipulation of woody plants creates a distinct disturbance type — physical tearing and pulling — different from bite-browsing by diprotodontids.

Thylacine (Thylacinus cynocephalus — thylacine, a pursuit mesopredator with wolf-like body form; confirmed from ~4 MYA onward)

Body mass: estimated 15–30 kg.
Ecology: coursing or stalking predator of small to medium prey. Not capable of killing adult megafauna. Likely crepuscular to nocturnal.
Constraint: imposes predation pressure on small to medium-bodied prey and on juveniles of larger species. Its confirmed early Pleistocene presence makes it the most secure named predator in this window.

Dromornithid lineage (dromornithids — giant flightless birds; the lineage was present in Sahul through this period)

Body mass range: 100–500+ kg across the lineage.
Ecology: herbivorous or omnivorous; large bill suited to processing tough plant material, seeds, or fruit. Not a predator. See Dromornithidae for full lineage context.
Constraint: imposed sustained vegetation pressure as large-bodied ground birds. Which genus is most appropriate for the ~2 MYA window remains unresolved; see Dromornithidae open questions.

Zaglossus species (giant long-beaked echidna — confirmed in New Guinea and formerly Australia through Pleistocene)

Body mass: estimated 5–15 kg depending on species (substantially larger than modern echidnas).
Ecology: long-beaked echidna relatives specialised for probing soil and leaf litter for earthworms and invertebrates.
Constraint: ecosystem indicator; their presence requires sufficient invertebrate-rich soil layers to support a specialised large consumer.

Tier 2 — Lineage-level constraint secure; named species assignment uncertain

These lineages were present in Sahul's early Pleistocene; the named species best known from the literature are from a later window and should not be cited by name for ~2 MYA lore without additional qualification.

Thylacoleonid lineage (marsupial lion-grade predators — the family Thylacoleonidae; large-bodied ambush predator role in woodland and forest margins)

Ecology: powerful forelimbs with retractile claws, specialised shearing bite. Ambush or short-burst attack strategy. Occupied woodland and forest margin habitats.
Constraint: the thylacoleonid lineage imposed apex ambush predation risk at forest-woodland edges. This constraint applies to the ~2 MYA window regardless of which species was present. Use "thylacoleonid predator" or "marsupial lion-grade predator" rather than Thylacoleo carnifex unless the ~2 MYA assignment of that species is specifically confirmed. See Tier 3 for T. carnifex as a later analogue.

Large varanid predator (giant monitor lizard lineage — very large-bodied varanids were present in early Pleistocene Sahul)

Ecology: Komodo-parallel predation strategy: ambush predator, venomous bite, opportunistic carrion consumer. Open and semi-open habitats.
Constraint: large varanid predation risk in open terrain and at carcass sites is a secure baseline pressure for ~2 MYA Sahul. Body size estimates are uncertain; conservative estimates are still consistent with a major predator. Use "large varanid predator" or "Megalania-grade monitor" rather than Varanus priscus unless the ~2 MYA presence of that species is specifically confirmed.

Large semi-terrestrial crocodilian (Quinkana lineage — longer-legged semi-terrestrial crocodilians; genus represented in Pliocene–early Pleistocene Sahul)

Ecology: capable of terrestrial movement beyond water margins. Associated with riparian and wetland zones but not strictly aquatic.
Constraint: semi-terrestrial crocodilian predation risk in riparian corridors, extending beyond the immediate waterline. Use "Quinkana-grade crocodilian" or "large semi-terrestrial crocodilian" rather than Q. fortirostrum, which is the late-Pleistocene representative.

Tier 3 — Later-Pleistocene named species (valid analogues, not confirmed at ~2 MYA)

These are the best-documented representatives of their lineages and valid constraint templates. Their presence at ~2 MYA is not confirmed; they are included here as reference points for the constraint logic, not as confirmed ~2 MYA actors.

Diprotodon optatum (Diprotodon — the largest known marsupial; earliest confirmed fossils ~1.6 MYA)

Body mass: estimated 1,000–2,800 kg.
Constraint template: this is the best-documented diprotodontid and defines what a maximum-grade diprotodontid pressure looks like. The ~2 MYA window likely had diprotodontid-grade animals; Diprotodon optatum itself may have appeared at or slightly after this window.

Thylacoleo carnifex (marsupial lion — earliest confirmed fossils ~1.6–2 MYA)

Body mass: estimated 100–160 kg.
Constraint template: best-documented thylacoleonid. The ~2 MYA assignment is plausible but not definitively established. Use as an analogue for thylacoleonid pressure; do not cite as a confirmed ~2 MYA species without qualification.

Tier 4 — Excluded from ~2 MYA window

Procoptodon goliah (giant short-faced kangaroo)

Fossil record: predominantly ~500 kya to ~40 kya. Not confirmed at ~2 MYA and almost certainly absent. Do not use for ~2 MYA lore.

Genyornis newtoni (dromornithid)

Fossil record: predominantly ~700 kya to ~40 kya. Not confirmed at ~2 MYA. The dromornithid lineage was present; use Tier 1 dromornithid lineage framing instead.

Constraints

No single locality within the early Pleistocene window contained the full Tier 1 assemblage simultaneously; local and regional variation was significant.
Tier 2 lineages impose real pressure that lore must account for; the uncertainty is about species identity, not about whether those pressure types were present.
Tier 3 species are valid for illustrating what a lineage's pressure looks like but must not be stated as confirmed ~2 MYA actors without qualification.
Size estimates for all large-bodied taxa involve substantial uncertainty; constraint implications are robust to this uncertainty but specific mass figures should not be treated as precise.

System Implications

The combined megafauna guild defined by Tier 1 and Tier 2 entries imposes layered herbivore consumption, predation risk, and disturbance pressure across all productive landscape zones.
Multiple predator types at different ecological levels created overlapping predation risk across terrain types; no single habitat type was risk-free.
Large herbivore consumption and large predator presence co-occurred in productive zones; high food value and high risk were not spatially separated.

Known Variability

Regional assemblages varied; New Guinea highlands had different assemblages from northern Australian lowlands.
Tier 2 lineage representatives may have differed in body size and exact hunting strategy from their better-known Tier 3 analogues; the constraint type is the same but the intensity may differ.
Fossil record gaps mean some taxa may have been present at ~2 MYA but are not yet documented; the catalog represents known taxa, not a complete inventory.

Open Questions

Which dromornithid genus is most appropriate for the ~2 MYA representative window in northern Sahul?
Was Thylacoleo carnifex present at ~2 MYA or does the ~2 MYA window represent an earlier thylacoleonid species?
Was a large varanid predator confirmed in New Guinea at ~2 MYA, or was its presence restricted to mainland Australia in this window?

Used By Lore

Diprotodontid Domestication and Working Lineages

Cassowary World