Morphological Measurements

Size and shape characters are quantified and reported as lengths or indices. Measurements are normally recorded in thousandths of a millimetre but reported to the nearest hundredth as a range from minimum to maximum across all measured specimens. The majority of measurements were made with a stereomicroscope using a dual-axis stage micrometer wired to digital readouts although some were made using an ocular micrometer.

CFW: Clypeal fork width measured between the anterior-most points of the clypeal teeth.

CI (cephalic index): HW/HL x 100.

EI (eye index): EL/HW x 100.

EL: Measured in one of two ways: (1) Maximum eye length or (2) maximum eye length measured in full face view.

EW: Measured one of two ways: (1) Maximum eye width or (2) maximum eye width measured in full face view.

HFL: Maximum length of hind femur, measured in anterior view.

HL: Maximum head length in full-face (dorsal) view, measured from the anterior-most point of the clypeal margin or the midpoint of a line drawn across the anterior-most points of the clypeal teeth to the posterior-most point of the head or the midpoint of a line drawn across the posterior margin of the head.

HTL: Maximum length of hind tibia, excluding the proximal part of the articulation which is received into the distal end of the hind femur.

HW: Maximum head width in full face (dorsal) view, excluding the eyes.

ML: Mesosomal length measured from the anterior surface of the pronotum proper (excluding the collar) to the posterior extension of the propodeal lobes or metapleural flanges measured in lateral (side) view.

MTL: Maximum length of mid tibia, excluding the proximal part of the articulation which is received into the distal end of the femur.

PetI (petiolar index): PetW/PetL x 100.

PetL: Maximum length of the petiolar node in dorsal view.

PetW: Maximum width of the petiolar node in dorsal view.

PnL: Pronotal length measured from the anterior edge of the pronotal collar to the pronotal-mesonotal suture parallel to the measuring axis.

PpH: Maximum height of propodeum measured tangentially to the line measuring PpL.

PpL: Propodeal length measured from the metanotal groove to the posterior-most point of the propodeal lobes or metapleural flanges measured in lateral (side) view.

PronW: Maximum width of the pronotum in dorsal view.

REL: Relative Eye Length: EL/HW x 100.

SI (scape index): SL/HW x 100.

SL: Length of the scape (first antennal segment) excluding the basal neck and condyle.

The following are used for Crematogaster by Longino (2003):

HL: head length; perpendicular distance from line tangent to rearmost points of vertex margin to line tangent to anteriormost projections of clypeus, in full face view.

HW: head width; maximum width of head in face view, including eyes if they project ZOOTAXA beyond the sides of the head.

HC: head capsule width; maximum width of head in full-face view, excluding eyes; may be anterior or posterior to eyes.

SL: scape length; length of scape shaft from apex to basal flange, not including basal condyle and neck.

EL: eye length, measured along maximum diameter.

A11L, A10L, A09L, A08L: length of 11th to 8th antennal segment.

A11W, A10W, A09W, A08W: width of 11th to 8th antennal segment.

WL: Weber's length; viewing mesosoma in lateral profile, distance from approximate inflection point, where downward sloping pronotum curves into anteriorly projecting neck, to posteroventral propodeal lobes.

SPL: propodeal spine length; measured from tip of propodeal spine to closest point on outer rim of propodeal spiracle.

PTH: petiole height; viewed in lateral profile, perpendicular distance from ventral margin to highest point of posterolateral tubercles; if ventral margin is concave upward, measured from line tangent to uppermost portion of curve and oriented as close as possible to long axis of petiole.

PTL: petiole length; viewed in lateral profile and measured in same plane as anterodorsal face, distance from inflection point marking juncture of posterolateral lobes and cylindrical posterior portion of segment to anterior inflection point where petiole curves up to condyle or, if inflection point not visible, where petiole is obscured by posteroventral lobes of propodeum.

PTW: petiole width; maximum width of petiole in dorsal view.

PPL: postpetiole length; viewing at an angle that maximizes length (approximately parallel to fourth abdominal tergite), perpendicular distance from line tangent to anterior inflection point (narrowest point when postpetiole is hourglass-shaped where it joins the helcium, point immediately anterior to node when helcium is sharply differentiated from node as a distinct cylindrical stem) to line tangent to posteriormost lobes if bilobed, to posteriormost point if globular.

PPW: postpetiole width; maximum width of postpetiole, in same view as and perpendicular to postpetiole length.

CI: cephalic index; 100*HW/HL.

OI: ocular index; 100*EL/HL.

SI: scape index; 100*SL/HL.

SPI: propodeal spine index; 100*SPI/WL.

PTHI: petiole height index; 100*PTH/PTL.

PTWI: petiole width index; 100*PTW/PTL.

PPI: postpetiole width index; 100*PPW/PPL.

ACI: antennal club index. This index attempts to quantify the degree of distinctness of the club. The product of segment length and width is a proxy of overall segment size, and the index measures relative change in size from segment 10 to 9 compared to relative change from 9 to 8. A sharply differentiated two-segmented club will have segment 10 much larger than 9, and ZOOTAXA segment 9 about the same size as 8, and the index will be greater than zero. A club in which segments 10 to 8 gradually decrease in size will have similar first and second terms in the formula, and the index value will be near zero. A distinctly 3-segmented club will have a value less than zero.