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Mesa A Tyrannochthonius Pseudoscorpion (Tyrannochthonius sp. 'Mesa A' (WAM T81480))

The Mesa A Tyrannochthonius pseudoscorpion is a poorly known, unnamed pseudoscorpion recorded from Mesa A in the Pilbara. Its WA Priority 1 status and association with a subterranean fauna setting make precautionary assessment important before ground disturbance, although species-specific details are scarce.

Conservation status

Western Australia, WA Threatened and Priority Fauna List: Priority 1. This listing covers only Tyrannochthonius sp. 'Mesa A' (WAM T81480) (Priority 1).

Seasonal information

Seasonal activity and breeding information have not been documented for this taxon. The row below is a general planning window, not an indication of when the pseudoscorpion is active.

Species-specific season: Not documented.

Planning approach: Arrange assessment before disturbance and do not rely on a seasonal window to avoid impacts.

No months are known for this taxon. The season row is a general works-planning prompt only.

  • Survey and works planning: General planning window only. Species-specific activity months are unknown. Complete targeted assessment before disturbance, whatever the season.

Identification: Appearance and size

This is an unnamed pseudoscorpion identified to the genus Tyrannochthonius and tracked under the collection identifier WAM T81480.

Its colour, body form, distinguishing features and size have not been documented. Descriptions of other Tyrannochthonius species do not identify this animal.

Recorded name: Tyrannochthonius sp. 'Mesa A' (WAM T81480)

Identification: Similar species and field signs

Similar species and taxon-specific field signs have not been documented. Pseudoscorpions are small arachnids, but group-level appearance alone is not enough to confirm this identification.

Document field observations and refer them to a suitably qualified arachnologist for identification.

Distribution: Known range

The taxon is recorded from the Pilbara, with Mesa A given in its name.

Mesa A in the Robe Valley is the only named locality associated with this taxon. Mesa A is one of three mesas on the west flank of the Robe River, approximately 47 km from the river mouth.

No public WA coordinates are available through the Atlas of Living Australia, and no coordinates for this taxon are stated.

Distribution: WA region and status

The DBCA priority list identifies the Pilbara region. The taxon is listed as Priority 1, meaning it is poorly known, known from few locations, and none of those locations are on conservation lands. This is a DBCA priority category, not a listing under the Biodiversity Conservation Act 2016. No national listing is given.

Habitat: Mesa setting

The taxon's precise habitat requirements have not been documented. Mesa formations in the Robe Valley support subterranean fauna.

Robe Valley troglofauna live in small voids and fissures in mesas, mostly in an iron ore formation. The exact substrate, depth or void type used by this pseudoscorpion is not known.

Habitat: Habitat limits

Do not assume that all parts of a mesa, or all subterranean habitats in the Pilbara, are occupied by this taxon. Its range and habitat extent remain poorly documented.

Foraging habitat: Available evidence

The taxon's feeding and foraging habitat have not been documented.

Its diet, prey, foraging behaviour and feeding location are not known. There is no basis for assigning it a particular food source or foraging zone.

Foraging habitat: Field precautions

During surveys, retain relevant material and record the exact sampling position and habitat context. Do not disturb or remove additional substrate solely to infer what the animal eats.

Breeding habitat: Breeding information

The breeding biology of this taxon is poorly known.

No breeding site, reproductive behaviour, number of young or breeding season has been documented. A breeding period or breeding habitat cannot be identified.

Breeding habitat: Planning implication

Do not use an assumed breeding season to determine when works can proceed. Plan assessment and avoidance around the potential for known mesa habitat to support the taxon throughout the year.

Sheltering habitat: Potential subterranean refuges

A precise sheltering site has not been documented. Small voids and fissures are habitat for Robe Valley mesa troglofauna generally.

Mesa voids and fissures provide relevant habitat context, but the exact refuge used by this species-level record is not known.

Sheltering habitat: Avoidance

Treat connected void-bearing mesa material as potentially relevant habitat during planning. Avoid unnecessary breakage, excavation or removal of such material while the taxon's occurrence and habitat limits remain poorly known.

Threats: Potential works pressures

No threats specific to this taxon have been documented. Mining and water extraction are potential pressures on subterranean communities in the Robe Valley.

Mining and water extraction may sometimes threaten subterranean communities. These are regional pressures, and no particular pressure has been measured for this taxon.

Threats: Uncertainty

The taxon is poorly known and recorded from few locations. Its population size, distribution beyond the named locality and response to disturbance have not been documented.

Survey methodology: 1. Review records and habitat

Targeted subterranean fauna surveys should be designed and interpreted by suitably experienced personnel. Regional troglofauna surveys have used traps in drill holes and monitoring wells, but there is no taxon-specific protocol.

Check the project area against the known Mesa A locality and assess whether it includes mesa landforms and potentially void-bearing material. Seek current DBCA advice and relevant collection or survey records because public coordinates are not available.

Survey methodology: 2. Use targeted methods and records

Troglofauna sampling in the Robe Valley has used traps, including PVC cylinders containing moist leaf material suspended in exploration drill holes and monitoring wells. A qualified subterranean fauna specialist should select methods, locations and effort appropriate to the site and obtain any required approvals.

Record sampling locations, depth or access point, substrate context, dates, method and identification confidence. Do not treat a non-detection as proof of absence without considering survey coverage and method limitations.

Vegetation associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific vegetation association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Ecosystem associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific ecosystem association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Soil and substrate associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific soil association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Water and wetland associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific water association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Fauna records and mapped habitat: Not yet analysed

Record locations can be overlaid with mapping, but record frequency alone does not measure habitat preference. No species is excluded from desktop assessments by this analysis.

No quality-controlled record-to-map analysis has been completed for this species. The existing generalised distribution dots and indicative range polygons have not been treated as precise occurrence coordinates.

A defensible run needs dated, independently attributable records, coordinate uncertainty, duplicate and captive-record checks, layer versions and regional scope. Preference and absence require additional survey-effort and detection evidence.

Habitat limitations and contrary evidence: No supported exclusion recorded

Not recorded is not the same as cannot occur. Low suitability, resident habitat, breeding habitat and occasional movement are different conclusions.

This library has not established a vegetation, ecosystem or soil-type exclusion for this species. This does not mean all habitat is suitable; the evidence needed to justify an exclusion has not been assembled.

Habitat limitations and contrary evidence: Before using a negative association

  • Confirm the taxon, geographic region, life stage and habitat function covered by the evidence.
  • Check survey methods, season, repeated effort and detectability before interpreting non-detection.
  • Investigate credible contradictory records and microhabitats absent from broad mapping.
  • Do not convert a missing map class, low record count or failed data request into species absence.

Before habitat disturbance: 1. Desktop assessment

Assess the potential for the taxon to occur before clearing or excavation affects mesa habitat.

Confirm the proposed works footprint, landform and proximity to Mesa A. Review the DBCA priority listing, project surveys and available subterranean fauna records, and consult DBCA or a qualified specialist where the record is relevant to the works.

Before habitat disturbance: 2. Survey and avoidance planning

Where suitable mesa habitat could be affected, arrange targeted assessment before disturbance and allow time for specialist identification and regulatory advice. Map areas to avoid and brief the crew on exclusion boundaries, access routes and stop-work requirements.

During habitat disturbance: 1. Keep within the approved footprint

Use controlled work practices where disturbance could affect mesa material or suspected subterranean habitat.

Mark and maintain exclusion areas and avoid unnecessary excavation, crushing or stockpiling of material outside the approved footprint. Keep machinery and access routes away from areas set aside for habitat protection.

During habitat disturbance: 2. Stop and seek advice

If a potentially relevant void, unusual specimen or unexpected habitat is encountered, pause work in the immediate area, protect the find from further disturbance and contact the fauna spotter catcher or project ecologist.

Do not attempt an unqualified identification or relocate a specimen unless directed under an approved procedure.

After habitat disturbance: 1. Check and document

After work, confirm that disturbance stayed within the approved area and follow up any fauna observations.

Inspect the work area and exclusion boundaries for unauthorised disturbance. Record any finds, incidents, habitat changes and corrective actions in the project fauna records.

After habitat disturbance: 2. Escalate new information

Arrange expert identification of any collected or observed specimens through the approved process. Report relevant new records and incidents to the project ecologist and follow applicable approval and DBCA requirements.

Rehabilitation actions: 1. Stabilise disturbed areas

No rehabilitation method has been shown to work for this taxon. Preventing further disturbance to potentially suitable mesa habitat is the primary precaution.

Rehabilitate disturbed ground in line with the approved site plan, focusing on stabilising exposed material and preventing erosion or further encroachment into retained habitat. Do not assume reinstatement will restore subterranean habitat conditions.

Rehabilitation actions: 2. Monitor and report

Check rehabilitated areas for compliance with the project plan and record any issues. Seek specialist advice before moving or replacing excavated material where it may contain voids or fauna.

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