Order Dorylaimida Pearse, 1936

Key from Jairajpuri and Ahmad (1992) with slight modification.

1

a

Feeding apparatus an odontostyle

Dorylaimina

b

Feeding apparatus a mural tooth

2

2

a

Mural tooth located on subdorsal wall of buccal cavity; basal part of esophagus small with a strongly-developed triquetrous chamber

Campydorina

b

Mural tooth located on subventral wall of buccal cavity; basal part of esophagus fairly long and without triquetrous chamber

Nygolaimina

Suborder Dorylaimina Pearse, 1936

1

a

Cheilostom strongly sclerotized, with plate- or basket-like structures, frequently with large onchia, with or without denticles

Actinolaimoidea

b

Cheilostom usually thin-walled, without onchia or denticles

2

2

a

Odontostyle long, attenuated; esophagus with three glands

Longidoroidea

b

Odontostyle comparatively small; esophagus with five glands

3

3

a

Expanded part of esophagus enclosed in a spiral muscular sheath

Belondiroidea

b

Expanded part of esophagus not enclosed in a spiral muscular sheath

4

4

a

Subcuticle coarsely striated, with abundant radial striae; expanded part of esophagus usually a small basal bulb

Tylencholaimoidea

b

Subcuticle not striated, few if any radial striae; expanded part of esophagus usually about 50% of total esophagus length

Dorylaimoidea

Superfamily Dorylaimoidea de Man, 1876

1

a

Odontostyle aperture wide, usually more than half odontostyle length; guiding ring plicated, not sclerotized

Aporcelaimidae

b

Odontostyle with smaller aperture, usually < 33% of odontostyle length; guiding ring sclerotized

2

2

a

Odontostyle attenuated, usually longer than lip region width

Nordiidae

b

Odontostyle not attenuated, usually about as long as lip region width

3

3

a

Large, stout nematodes, usually with long, filiform tail which exhibits sexual dimorphism

Dorylaimidae

b

Medium-sized nematodes with short tails which are similar in both sexes

Qudsianematidae

Family Dorylaimidae de Man, 1876

1

a

Cuticle with longitudinal ridges

2

b

Cuticle without longitudinal ridges

3

2

a

Tail elongate-conoid, similar in both sexes

Arctidorylaiminae

b

Tail elongate-conoid to filiform in females, short and bluntly rounded in males

Dorylaiminae

3

a

Cheilostom (between guiding ring and oral aperture) with minute to well-developed sclerotized plates; S₂N (nuclei of second pair of ventro-sublateral glands) well anterior to base of esophagus

Thornenematinae

b

Cheilostom without sclerotized plates; S₂N close to base of esophagus

Laimydorinae

Subfamily Dorylaiminae de Man, 1876

1

a

Ventromedian supplements in a contiguous series of 25-55

Dorylaimus

b

Ventromedian supplements in 2-3 groups (fascicles)

Ischiodorylaimus

Subfamily Laimydorinae Andrassy, 1969

1

a

Tails similar in both sexes

2

b

Tails dissimilar in males and females

4

2

a

Lip region offset; spicules narrow and "non-dorylaimoid"

Amphidorylaimus

b

Lip region continuous; spicules broad and dorylaimoid

3

3

a

Ventromedian supplements numerous, contiguous

Prodorylaimus

b

Ventromedian supplements few, spaced

Prodorylaimium

4

a

Guiding ring sclerotized, appearing double; male prerectum long, beginning anterior to supplements

5

b

Guiding ring not sclerotized, appearing single or weakly double; male prerectum short, beginning within range of supplements

6

5

a

Subcuticle with coarse striations

Idiodorylaimus

b

Subcuticle without coarse striations

Laimydorus

6

a

Male tail with rounded terminus

7

b

Male tail with pointed terminus

Afrodorylaimus

7

a

Odontostyle asymmetrical; two parts of esophagus not clearly demarcated

Drepanodorylaimus

b

Odontostyle symmetrical; two parts of esophagus clearly demarcated

8

8

a

Odontophore slightly swollen at base

Minidorylaimus

b

Odontophore rod like

9

9

a

Ventromedian supplements contiguous or uniformly spaced

10

b

Ventromedian supplements in two groups (fascicles)

Calodorylaimus

10

a

Cuticle thin, vulva not sclerotized; spicules comparatively weak; prerectum extending much beyond range of supplements

Miodorylaimus

b

Cuticle thick, vulva sclerotized; spicules well developed; prerectum beginning at anterior end or within range of supplements

11

11

a

Spicules large, with double contour on dorsal side and spur near tip; supplements very small

Calcaridorylaimus

b

Spicules without double contour on dorsal side and without spur near tip; supplements well developed

Mesodorylaimus

Subfamily Thornenematinae Siddiqi, 1969

1

a

Female reproductive system monovarial, opisthodelphic

2

b

Female reproductive system diovarial, amphidelphic

6

2

a

Female tail short, rounded

3

b

Female tail elongate-conoid to long, filiform

4

3

a

Labial and postlabial sclerotization

Sclerolabia

b

No labial or postlabial sclerotization

Willinema

4

a

Tail elongate-conoid, similar in both sexes

Indiodorylaimus

b

Tail elongate-conoid to long, filiform in females and short-conoid in males

5

5

a

Odontostyle broad, with wide lumen and aperture; no labial sclerotization

Opisthodorylaimus

b

Odontostyle narrow, labial sclerotization

Thornenema

6

a

Odontostyle broad, with wide lumen and aperture; no labial sclerotization

Coomansinema

b

Odontostyle relatively narrow, labial sclerotization

7

7

a

Cheilorhabdions  strongly sclerotized, forming chamber-like structure

8

b

Cheilorhabdions  sclerotized, but not forming chamber-like structure

9

8

a

Guiding ring single, plicated; tail short, bluntly rounded

Silvallis

b

Guiding ring appears double; tail long, filiform

Fuscheila

9

a

Female tail short and rounded

Timminema

b

Female tail long and filiform

Sicaguttur

Subfamily Arctidorylaiminae Mulvey and Anderson, 1979

Arctidorylaimus

Family Aporcelaimidae Heyns, 1965

1

a

Body sharply tapering towards anterior end

Paraxonchiinae

b

Body not sharply tapering towards anterior end

2

2

a

Odontostyle axial with wide aperture

Aporcelaiminae

b

Odontostyle a mural tooth

Sectonematinae

Subfamily Aporcelaiminae Heyns, 1965

1

a

Cuticular layers inconspicuous; no criss-cross lines or punctations

2

b

Cuticular layers conspicuous; transverse of criss-cross lines or punctations

3

2

a

Female tail long, filiform

Aporcedorus

b

Female tail short, conoid

Aporcelaimium

3

a

Lip region offset by slight depression; vulva longitudinal

Makatinus

b

Lip region offset by deep constriction; vulva lips a transverse slit or pore-like

4

4

a

Lip region rounded, labial papillae not projecting above contour; two ventromedian supplements

Akrotonus

b

Lip region angular, labial papillae projecting above contour; >2 ventromedian supplements

5

5

a

Body very long (9-11 mm); aperture of odontostyle 1/3 its length

Tubixaba

b

Body <6mm; odontostyle aperture about ½ its length or greater

6

6

a

Cuticle with faint longitudinal markings or criss-cross lines

7

b

Cuticle with transverse striations

8

7

a

Body relatively small; three cardia glands at esophago-intestinal junction

Torumanawa

b

Body large; cardia glands absent

Aporcelaimus

8

a

Oral aperture circular

Takamangi

b

Oral aperture hexagonal

Aporcelaimellus

Subfamily Sectonematinae Siddiqi, 1969

Sectonema

Subfamily Paraxonchiinae Dhanachand and Jairajpuri, 1981

1

a

Odontostyle long, straight, attenuated, with small aperture; cardia glands poorly developed

Gopalus

b

Odontostyle smaller, wide, a little bent, with larger aperture; cardia glands well-developed

Paraxonchium

Family Qudsianematidae Jairajpuri, 1965

1

a

Cuticle with coarse transverse striations

2

b

Cuticle with fine transverse striations

3

2

a

Body slender; body pores indistinct; odontostyle attenuated

Crateronematinae

b

Body not slender; body pores distinct; odontostyle not attenuated

Lordellonematinae

3

a

Lip region discoid; well-developed hypodermal glands

Discolaiminae

b

Lip region not discoid; hypodermal glands absent or poorly developed

4

4

a

Lip region continuous with body contour; lips amalgamated

5

b

Lip region offset; lips usually separated

6

5

a

Tail short and hemispherical in both sexes; only one adanal pair of supplements present (rarely a single ventromedian)

Thorniinae

b

Tail elongate conoid in both sexes; adanal pair and a series of ventromedian supplements present

Chrysonematinae

6

a

Dorsal esophageal gland nucleus near anterior of esophageal enlargement; female tail short, hemispherical to elongate conoid

Qudsianematinae

b

Dorsal esophageal gland nucleus two or more body widths behind anterior of esophageal enlargement; female tail long, filiform

Hulqinae

Subfamily Qudsianematinae Jairajpuri, 1965

1

a

Female reproductive system monovarial, opisthodelphic

2

b

Female reproductive system diovarial, amphidelphic

3

2

a

Amphids labial

Indokochinema

b

Amphids post-labial

Ecumenicus

3

a

Odontophore simple, rod-like

4

b

Odontophore flanged or with basal knobs

13

4

a

Odontostyle large; guiding ring appears double

5

b

Odontostyle small; guiding ring appears single

6

5

a

Lip region with deeply sunken circumoral area and distinct inner liplets

Labronemella

b

Lip region without deeply sunken circumoral area; inner liplets not well separated; odontostyle slender

Labronema

6

a

Outer margin of lips forming flap over oral area; inner margin of lips sunken

Baqriella

b

Outer margin of lips not forming flap over oral area; inner margin of lips not sunken

7

7

a

Constriction between slender and expanded parts of esophagus; expanded part bipartite

Skibbernema

b

No constriction between slender and expanded parts of esophagus; expanded part not bipartite

8

8

a

Lips with cuticularized pieces

Crassolabium

b

Lips without cuticularized pieces

9

9

a

Cardia disk present

Thonus

b

Cardia disk absent

10

10

a

Tail elongate conoid, 3.5-8.0 x anal body diameter.

Epidorylaimus

b

Tail short-conoid, 1-3 x anal body diameter

11

11

a

Body small (<1mm); esophagus long, almost 1/3 body length

Microdorylaimus

b

Body long (>1mm); esophagus short

12

12

a

Precloacal space present

Eudorylaimus

b

Precloacal space absent

Allodorylaimus

13

a

Odontophore flanged

14

b

Odontophore with three prominent knobs

Tylenchodorus

14

a

Odontostyle thick-walled

Pachydorylaimus

b

Odontostyle thin-walled

Qudsianema

Subfamily Thorniinae De Coninck, 1965

1

a

Males with large ventromedian supplements and small gubernaculum

Nygolaimoides

b

Males without ventromedian supplements or gubernaculum

2

2

a

Amphids stirrup-shaped, aperture as wide as fovea; spicules not dorylaimoid, lateral guiding pieces absent

Thornia

b

Amphids oval, aperture smaller than fovea; spicules  dorylaimoid with lateral guiding pieces

Thorneella

Subfamily Crateronematinae Siddiqi, 1969

Crateronema

Subfamily Chrysonematinae Siddiqi, 1969

1

a

Lips rounded; female tail long, conoid; male tail short, convex-conoid

Chrysonema

b

Lips knob-like; tail in both sexes elongate-conoid, ventrally-curved

Chrysonemoides

Subfamily Discolaiminae Siddiqi, 1969

1

a

Lip region with cuticularized, shallow, bowl-like plates

Mylodiscus

b

Lip region without cuticularized plates

2

2

a

Lip region discoid

Discolaimus

b

Lip region not discoid

3

3

a

Lip region offset by an expansion

Discolaimoides

b

Lip region offset by a constriction

4

4

a

Female reproductive system diovarial, amphidelphic

Discolaimium

b

Female reproductive system monovarial, opisthodelphic

Latocephalus

Subfamily Lordellonematinae Siddiqi, 1969

1

a

Body pores indistinct; female reproductive system monovarial, opisthodelphic

Sicorinema

b

Body pores distinct; female reproductive system monovarial, prodelphic

2

2

a

Ventral body pores only in esophageal region; tail elongate-conoid, bent dorsally

Poronemella

b

Ventral body pores along entire body; tail short-conoid, or subdigitate

3

3

a

Odontostyle aperture > 1/2 its length; spicules non-dorylaimoid

Moshajia

b

Odontostyle aperture < 1/2 its length; spicules dorylaimoid

Lordellonema

Subfamily Hulqinae Siddiqi, 1982

1

a

Female reproductive system monovarial, opisthodelphic

Hulqus

b

Female reproductive system diovarial, amphidelphic

Mitoaxonchium

Family Nordiidae Jairajpuri and Siddiqi, 1964

1

a

Labial papillae rising above lip contour

2

b

Labial papillae not enlarged

3

2

a

Cuticle with longitudinal and horizontal lamelliform striations

Helmabiinae

b

Cuticle smooth, striations absent

Cephalodorylaiminae

3

a

Odontophore usually flanged

Pungentiinae

b

Odontophore not flanged

4

4

a

Body usually robust; odontostyle length 3-5 x lip region width

Nordiinae

b

Body usually slender; odontostyle length < 2 x lip region width

Actinolaimoidinae

Subfamily Nordiinae Jairajpuri and Siddiqi, 1964

1

a

Body robust; odontostyle length 3-5 x lip region width

Longidorella/Saevadorella

b

Body slender; odontostyle length < 2 x lip region width

Thornedia

Subfamily Cephalodorylaiminae Jairajpuri, 1967

1

a

Inner labial papillae setiform; female reproductive system diovarial, amphidelphic

Cephalodorylaimus

b

Inner labial papillae barely raised; female reproductive system monovarial, prodelphic

Acephalodorylaimus

Subfamily Pungentiinae Siddiqi, 1969

1

a

Tail short to elongate-conoid

2

b

Tail long, filiform

6

2

a

Odontostyle very long, > 50 µm

Californidorus

b

Odontostyle shorter, < 50 µm

3

3

a

Amphids labial

Kochinema

b

Amphids post-labial

4

4

a

Cuticle near vulva coarsely striated

Rhyssocolpus

b

Cuticle near vulva not striated

5

5

a

Cuticularized platelets around stoma

Pungentus

b

No cuticularized platelets around stoma

Enchodelus

6

a

Odontostyle  < 10 µm; ventromedian supplements few and spaced

Enchodorus

b

Odontostyle  > 15 µm; ventromedian supplements numerous and contiguous

Lenonchium

Subgenera of Enchodelus Thorne, 1939

1

a

Tail hemispherical or bluntly conoid

2

b

Tail short-conoid or elongate-conoid

3

2

a

Odontostyle fairly long; odontophore with broad basal flanges

Enchodelus

b

Odontostyle short; odontophore without basal flanges

Rotundus

3

a

Lip region not offset from body contour; female gonads with ovoid chamber

Heterodorus

b

Lip region distinctly offset from body contour; female gonads without ovoid chamber

4

4

a

Odontostyle>50µm; odontophore with moderate basal flanges

Nepalus

b

Odontostyle<50µm; odontophore rod-like

Paraenchodelus

Subfamily Helmabiinae Siddiqi, 1971

Helmabia

Subfamily Actinolaimoidinae Jairajpuri and Ahmad, 1992

1

a

Odontostyle very narrow; aperture indistinct

2

b

Odontostyle narrow; aperture distinct

3

2

a

Labial papillae prominent; projecting above lip contour

Malekus

b

Labial papillae indistinct; not projecting above lip contour

Oonaguntus

3

a

Lip region continuous; first pair of ventro-sub-lateral esophageal glands close together

Actinolaimoides

b

Lip region offset; first pair of ventro-sub-lateral esophageal glands widely separated

4

4

a

Odontostyle usually < 2 lip widths long; well-developed glands at esophago-intestinal junction

Oriverutus

b

Odontostyle usually 3 lip widths long; no glands at esophago-intestinal junction

Pararoriverutus

Superfamily Actinolaimoidea Thorne, 1939

1

a

Female tail < 2x abd, conical or rounded; vestibule with basket-like structures

Carcharolaimidae

b

Female tail >4x abd; vestibule without basket-like structures

2

2

a

Vestibule with four massive onchia, with or without denticles

Actinolaimidae

b

Vestibule without onchia but with corrugated ring and tranverse rows of mural denticles

Trachypleurosidae

Family Actinolaimidae Thorne, 1939

1

a

Cuticle with longitudinal striations

2

b

Cuticle without longitudinal striations

3

2

a

Odontostyle massive, robust, aperture 1/2 its length

Actinolaiminae

b

Odontostyle slender, 2-3 lip widths long; aperture about 1/3 its length

Brittonematinae

3

a

Vestibule with minute denticles

Paractinolaiminae

b

Vestibule without denticles

Neoactinolaiminae

Subfamily Actinolaiminae Thorne, 1939

Actinolaimus

Subfamily Neoactinolaiminae Thorne, 1967

1

a

Vestibule with four onchia

2

b

Vestibule with six onchia

Hexactinolaimus

2

a

Onchia fused into a strong second spear guide

Metactinolaimus

b

Onchia not fused

3

3

a

Ventromedian supplements in 2-3 fascicles

Neoactinolaimus

b

Ventromedian supplements arranged in series

Egtitus

Subfamily Paractinolaiminae Thorne, 1967

1

a

Tail elongate-conoid to filiform; similar in both sexes

2

b

Tail elongate-conoid to filiform in females, short conoid in males

3

2

a

Esophago-intestinal junction with prominent glands

Trachactinolaimus

b

Esophago-intestinal junction without glands

Dominicactinolaimus

3

a

Ventromedian supplements in series

4

b

Ventromedian supplements in fascicles

Afractinolaimus

4

a

Vestibule with massive basket-like ribs

Westindicus

b

Vestibule without ribs

Paractinolaimus

Subfamily Brittonematinae Thorne, 1967

1

a

Lip region almost continuous with body; female tail long, filiform; male tail short, rounded

Actinca

b

Lip region expanded; tail long, filiform in both sexes

Paractinocephalus

Subgenera of Actinca Andrassy, 1964

1

a

Lip region narrow and high; vestibule ring weak

Actinca

b

Lip region wide and low; vestibule ring well developed

2

2

a

Body < 3 mm, odontostyle slender

Stomachoglossa

b

Body > 3 mm, odontostyle robust

Parastomachoglossa

Family Trachypleurosidae Thorne, 1967

Trachypleurosum

Family Carcharolaimidae Thorne, 1967

1

a

Stoma narrowing behind guiding ring

Carcharolaiminae

b

Stoma not narrowing behind guiding ring

Caribenematinae

Subfamily Carcharolaiminae Thorne, 1967

1

a

Lip region offset; tail conoid; curved ventrally

2

b

Lip region continuous; tail elongate, straight

Brasilaimus

2

a

Lips angular, petaloid, bearing rods and plates

Antholaimus

b

Lips not angular, without rods and plates

3

3

a

Cephalic framework basket-like

4

b

Cephalic framework with two plates, posterior one shallow, bowl-like, anterior small

Mylodiscoides

4

a

Cephalic framework with strong onchia

5

b

Cephalic framework with ribs, denticles or small teeth

Carcharolaimus

5

a

Six onchia

Carcharoides

b

Four onchia

Caryboca

Subfamily Caribenematinae Thorne, 1967

Caribenema

Superfamily Longidoroidea Thorne, 1935

1

a

Guiding ring double; odontophore flanged

Xiphinematidae

b

Guiding ring single; odontophore not flanged

Longidoridae

Family Longidoridae Thorne, 1935

1

a

Amphids with stirrup-shaped fovea

Paralongidorus

b

Amphids with pouch-like fovea

2

2

a

Amphid apertures pore-like, inconspicuous

Longidorus

b

Amphid apertures slit-like

Longidoroides

Family Xiphinematidae Dalmasso, 1969

1

a

Amphids stirrup-shaped with slit-like apertures; dorsal gland nucleus at same level as dorsal gland opening

Xiphinematinae

b

Amphids pouch-like with pore-like apertures; dorsal gland nucleus far behind dorsal gland opening

Xiphidorinae

Subfamily Xiphinematinae Dalmasso, 1969

Xiphinema

Subfamily Xiphidorinae Khan, Chawla and Saha, 1978

Xiphidorus

Superfamily Belondiroidea Thorne, 1939

Belondiridae

Family BelondiridaeThorne, 1939

1

a

Cuticularized pieces around oral aperture; odontophore flanged

Dorylaimellinae

b

Cuticularized pieces absent around oral aperture; odontophore rod-like

2

2

a

Female tail short; digitate, conoid or rounded

Belondirinae

b

Female tail long, filiform

Swangeriinae

Subfamily BelondirinaeThorne, 1939

1

a

Female reproductive system diovarial, amphidelphic

2

b

Female reproductive system monovarial, opisthodelphic

4

2

a

Anterior of esophagus set off by constriction

Anchobelondira

b

Anterior of esophagus not set off by constriction

3

3

a

Lip region with 6 liplets; 2 ventromedian supplements

Belondirella

b

Lip region without liplets, no ventromedian supplements

Amphibelondira

4

a

Esophagus > 1/2  body length; vulva anterior to esophago-intestinal junction

Nimigula

b

Esophagus < ½ body length; vulva posterior to esophago-intestinal junction

5

5

a

Anterior of esophagus set off by constriction or isthmus

6

b

Anterior part of esophagus continuous

Belondira

6

a

Tail apically digitate

b

Tail apically hemispherical

7

a

Spicules very long, narrow, alate, without median pieces

Phallaxonchium

b

Spicules massive, non-alate, with median pieces

8

8

a

Odontostyle narrow, > 2 lip widths long

Heynsaxonchium

b

Odontostyle fusiform to cylindroid, < 2 lip widths long

9

9

a

Labial framework semi-sclerotized, cephalic papillae mammiform, anterior of esophagus non-muscular

Axonchoides

b

Labial framework not sclerotized, cephalic papillae not mammiform, anterior of esophagus muscular

Axonchium

Subgenera of Axonchium Cobb, 1920

1

a

Lip region not offset, bluntly conoid to hemispherical, lips amalgamated

Syncheilaxonchium

b

Lip region offset

2

2

a

>100 lateral body pores, > 50 ventral body pores; 5-7 caudal pores in female, 7-10 in male; spiral muscle sheath encircling posterior part of esophagus

Poraxonchium

b

Fewer lateral and ventral body pores; 1-2 caudal pores in female, up to 6 in male; muscle sheath with straight bundles encircling posterior part of esophagus

3

3

a

Vagina sclerotized

4

b

Vagina not sclerotized

7

4

a

Disk-like structure between body cuticle and vaginal sclerotization; males with many contiguous supplements

Discaxonchium

b

No disk-like structure between body cuticle and vaginal scerotization; males with spaced supplements

5

5

a

Anterior part of esophagus separated by an isthmus; spicules arcuate; ventromedian supplements regularly spaced

6

b

Anterior part of esophagus not separated by an isthmus; spicules plow-shaped; ventromedian supplements poorly developed, in two groups

Spiculaxonchium

6

a

Anterior part of esophagus slender, with fusiform section; male spicules > 2x anal body diameter long

Epaxonchium

b

Anterior part of esophagus muscular, without fusiform section; male spicules smaller

Metaxonchium

7

a

Vulva broad, longitudinally oval, vagina lumen wide

Hypaxonchium

b

Vulva a transverse slit, vagina lumen narrow

Axonchium

Subfamily Dorylaimellinae Jairajpuri, 1964

Dorylaimellus

Subgenera of Dorylaimellus Cobb, 1913

1

a

Female reproductive system monovarial

2

b

Female reproductive system diovarial, amphidelphic

6

2

a

Female reproductive system monovarial, prodelphic

3

b

Female reproductive system monovarial, opisthodelphic

4

3

a

Vulva a transverse slit

Mesodorylaimellus

b

Vulva a longitudinal slit

Ibadanus

4

a

Peri-oral disk present, odontostyle attenuated

Sindellus

b

Peri-oral disk absent, odontostyle lumen distinct

5

5

a

Tail hemispherical or conoid

Metadorylaimellus

b

Tail long, attenuated

Amazonema

6

a

Lip region continuous with body contour

Capitellus

b

Lip region offset

7

7

a

Peri-oral disk present

8

b

Peri-oral disk absent

10

8

a

Vulva transverse

Axodorylaimellus

b

Vulva pore-like or longitudinal

9

9

a

Vulva longitudinal; tail cylindroid or sub-cylindroid

Belondorylaimellus

b

Vulva pore-like; tail elongate, attenuated

Jamilius

10

a

Vulva transverse

Rashidanema

b

Vulva longitudinal

11

11

a

Tail terminus clavate

Clavidorylaimellus

b

Tail terminus not clavate

12

12

a

Tail digitate or subdigitate

Dorylaimellus

b

Tail elongate-conoid to filiform

13

13

a

Tail very long (c=8-16); spicules with abrupt ventral angle; ventromedian supplements in pairs

Elongidorylaimellus

b

Tail long (c=4-5); spicules dorylaimoid; ventromedian supplements in pairs

Filidorylaimellus

Subfamily Swangeriinae Jairajpuri, 1964

1

a

Tail similar in both sexes

2

b

Tail dissimilar in both sexes

7

2

a

Basket-like structure around oral aperture

Swangeria

b

No basket-like structure around oral aperture

3

3

a

Cephalic sclerotization

Oxybelondira

b

No cephalic sclerotization

4

4

a

Odontostyle straight

5

b

Odontostyle asymmetrical

6

5

a

Body length < 2mm; female tail with lateral expansions; few ventromedian supplements

Falcihasta

b

Body length > 3mm; female tail without lateral expansions; numerous ventromedian supplements

Paraoxydirus

6

a

Odontostyle long, attenuated

Qudsiella

b

Odontostyle short, not attenuated

Oxydirus

7

a

Odontostyle narrow; weak labial basket present

Lindseyus

b

Odontostyle fusiform; labial basket absent

Roqueus

Superfamily Tylencholaimoidea Filipjev, 1934

1

a

Esophagus with 3 sections

Aulolaimoididae

b

Esophagus with 2 sections

2

2

a

Odontostyle usually well developed; expanded part of esophagus about 1/2 esophagus length

b

Odontostyle slender; expanded part of esophagus short, cylindroid or pyriform

Tylencholaimidae

3

a

Odontostyle asymmetrical, aperture distinct; esophageal bulb cylindroid

Mydonomidae

b

Odontostyle symmetrical, attenuated, often solid, needle-like; esophageal bulb usually pyriform

Leptonchidae

Family Tylencholaimidae Filipjev, 1934

1

a

Amphids small, pouch-shaped, with oval aperture; odontostyle asymmetrical

Mumtaziinae

b

Amphids stirrup-shaped, with slit-like aperture; odontostyle symmetrical

2

2

a

Odontostyle massive with very thick walls

Vanderlindiinae

b

Odontostyle not massive, walls not thick

3

3

a

Odontostyle long, attenuated with narrow lumen and aperture

Xiphinemellinae

b

Odontostyle generally small, with distinct lumen and aperture; odontophore usually knobbed

Tylencholaiminae

Subfamily Tylencholaiminae Filipjev, 1934

1

a

Amphid aperture small, pore-like

Tantunema

b

Amphid aperture slit-like

2

2

a

Odontophore with distinct basal knobs

3

b

Odontophore without basal knobs

4

3

a

Tail short-conoid or elongate-conoid

Tylencholaimus

b

Tail long, filiform

Discomyctus

4

a

Odontostyle 2 lip-region widths long

5

b

Odontostyle 1 lip-region width long

7

5

a

Body length < 1 mm; odontostyle long and very thin; vulva transverse

6

b

Body length  about 2 mm; odontostyle long and robust; vulva longitudinal

Chitwoodius

6

a

Female reproductive system monovarial, prodelphic

Meylonema

b

Female reproductive system diovarial, amphidelphic

Utahnema

7

a

Six sclerotized pieces around oral opening; labial disk absent; female reproductive system diovarial, amphidelphic

Sclerolaimus

b

Sclerotized pieces absent around oral opening; labial disk present; female reproductive system monovarial, prodelphic

Capilonchus

Subgenera of Tylencholaimus De Man, 1876

1

a

Labial disk present

Disctylencholaimus

b

Labial disk absent

2

2

a

Female reproductive system monovarial

3

b

Female reproductive system diovarial, amphidelphic

6

3

a

Female reproductive system prodelphic

4

b

Female reproductive system opisthodelphic

Opisthotylencholaimus

4

a

Lip region offset by deep constriction; odontophore with distinct basal knobs

5

b

Lip region offset by shallow depression; odontophore with very small basal knobs

Protylencholaimus

5

a

Tail short-conoid

Tylencholaimus

b

Tail elongate-conoid

Leptotylencholaimus

6

a

Odontostyle long, strongly cuticularized, small aperture

Pseudotylencholaimus

b

Odontostyle short, slender, with aperture 1/3 its length

Amphitylencholaimus

Subfamily Xiphinemellinae Jairajpuri, 1964

1

a

Female reproductive system monovarial prodelphic; tail long, filiform

Loncharionema

b

Female reproductive system diovarial, amphidelphic; tail short, conoid

2

2

a

Labial disk present

Xiphinemella

b

Labial disk absent

3

3

a

Stoma sclerotized; odontophore flanged; vulva transverse

Zalophidera

b

Stoma not sclerotized; odontophore without knobs or flanges; vulva pore-like

Kantbhala

Subfamily Vanderlindiinae Siddiqi, 1969

1

a

Odontostyle ventrally curved

2

b

Odontostyle straight

3

2

a

Odontostyle base furcate, two distinct parts of esophagus; vulva transverse

Curvidorylaimus

b

Odontostyle base not furcate, parts of esophagus not distinctly demarcated; vulva circular

Vanderlindia

3

a

Odontostyle aperture small; vulva transverse

Metadorylaimus

b

Odontostyle aperture large; vulva longitudinal

Neometadorylaimus

Subfamily Mumtaziinae Andrassy, 1976

1

a

Female reproductive system diovarial, amphidelphic; tail short, conoid

Promumtazium

b

Female reproductive system monovarial, opisthodelphic; tail long, filiform

Mumtazium

Family Leptonchidae Thorne, 1935

1

a

Cuticle heavily striated, both transversely and longitudinally forming a lamelliform pattern; cephalic setae present

Encholaiminae

b

Cuticle finely striated; no longitudinal straie or cephalic setae

2

2

a

Odontostyle asymmetrical; amphids strongly sclerotized

Athernematinae

b

Odontostyle symmetrical; amphids not sclerotized

3

3

a

Odontostyle solid, needle like, without distinct lumen

Belonenchinae

b

Odontostyle not solid, with distinct lumen

4

4

a

Odontophore with distinct knobs or flanges

Tylencholaimellinae

b

Odontophore without distinct knobs, rarely flanged

5

5

a

Odontostyle slender; inner cuticle lining of esophageal bulb not thickened

Leptonchinae

b

Odontostyle robust; inner cuticle lining of esophageal bulb distinctly thickened

Tyleptinae

Subfamily Leptonchinae Thorne, 1935

1

a

Esophageal bulb offset by Constriction

2

b

Esophageal bulb not offset by constriction

4

2

a

Lip region distinctly offset; labial disk present; female reproductive system diovarial; amphidelphic

Meylis

b

Lip region slightly offset; labial disk absent; female reproductive system monovarial; prodelphic

3

3

a

Odontophore flanged; tail digitate-spicate

Proleptonchoides

b

Odontophore not flanged; tail hemispherical or bluntly conoid

Proleptonchus

4

a

Vulva longitudinal; esophageal bulb cylindroid

Funaria

b

Vulva transverse or pore-like; esophageal bulb pyriform

5

5

a

Lip region continuous with body contour; stomal ring present

Bertzuckermania

b

Lip region offset; stomal ring absent

6

6

a

Odontophore sclerotized, arcuate; vulva transverse

Leptonchus

b

Odontophore sclerotized only at base, straight; vulva pore-like

Apoleptonchus

Subfamily Tyleptinae Jairajpuri, 1964

1

a

Labial disk present; odontostyle attenuated, with narrow lumen and aperture

Caveonchus

b

Labial disk absent; odontostyle robust, with wide lumen and aperture

2

2

a

Inner liplets around oral aperture; valvular chamber in esophageal bulb distinctly thickened

Tyleptus

b

Inner liplets absent around oral aperture; valvular chamber in esophageal bulb indistinct

Gymnotyleptus

Subfamily Belonenchinae Jairajpuri, 1964

1

a

Cuticle with punctations over entire body

Punctoleptus

b

Cuticle without punctations

2

2

a

Basal esophageal bulb pyriform with distinct, valvular thickenings

3

b

Basal esophageal bulb cylindrical, without valvular thickenings

4

3

a

Stoma heavily sclerotized at base; odontostyle long; odontophore conspicuously flanged

Sclerostylus

b

Stoma weakly sclerotized at base; odontostyle short; odontophore simple, rod-like or weakly flanged

Basirotyleptus

4

a

Labial disk present; odontophore with basal knobs

Glochidorella

b

Labial disk absent; odontophore flanged

Zetalaimus

Subgenera of Basirotyleptus Jairajpuri, 1964

1

a

Labial disk present

Coronatyleptus

b

Labial disk absent

2

2

a

Female reproductive system diovarial, amphidelphic

Aculonchus

b

Female reproductive system monovarial

3

3

a

Female reproductive system monovarial, prodelphic

Trichonchium

b

Female reproductive system monovarial; opisthodelphic

4

4

a

Odontophore flanged

Opisthotyleptus

b

Odontophore not flanged

Basirotyleptus

Subfamily Encholaiminae Golden and Murphy, 1967

Encholaimus

Subfamily Athernematinae Ahmad and Jairajpuri, 1978

Athernema

Subfamily Tylencholaimellinae Jairajpuri, 1964

1

a

Esophageal bulb not offset by constriction

2

b

Esophageal bulb offset by constriction

4

2

a

Tail long, filiform

Oostebrinkella

b

Tail short, rounded

3

3

a

Odontophore with basal knobs, female reproductive system monovarial, opisthodelphic

Gerthus

b

Odontophore without basal knobs, female reproductive system diovarial, amphidelphic

Goferus

4

a

Odontostyle with accessory stiffening piece

5

b

Odontostyle without accessory stiffening piece

6

5

a

Accessory stiffening piece on dorsal side of odontostyle; female reproductive system monovarial, opisthodelphic

Tylencholaimellus

b

Accessory stiffening piece on ventral side of odontostyle; female reproductive system monovarial, prodelphic

Dorella

6

a

Tail elongate

Agmodorus

b

Tail short and rounded

7

7

a

Sclerotized pieces absent around oral aperture; female reproductive system monovarial, opisthodelphic

Doryllium

b

Sclerotized pieces present around oral aperture; female reproductive system diovarial, amphidelphic

Phellonema

Subgenera of Tylencholaimellus Cobb, 1915

1

a

Labial disk present

Coronatylencholaimellus

b

Labial disk absent

Tylencholaimellus

Family Mydonomidae Thorne, 1964

1

a

Odontophore straight, rod-like; guiding ring thick

Calolaiminae

b

Odontophore angular; guiding ring not thick

Mydonominae

Subamily Mydonominae Thorne, 1964

1

a

Esophageal bulb enclosed in muscular sheath

Mydonomus

b

Esophageal bulb not enclosed in muscular sheath

2

2

a

Tail similar in both sexes

Dorylaimoides

b

Tail dissimilar in both sexes

Morasia

Subgenera of Dorylaimoides Thorne and Swanger, 1936

1

a

Female reproductive system diovarial, amphidelphic

2

b

Female reproductive system monovarial, opisthodelphic

4

2

a

Tail long, filiform

Longidorylaimoides

b

Tail not long and filiform

3

3

a

Tail short, conoid to hemispheroid

Dorylaimoides

b

Tail subdigtate or bent dorsally

Digidorylaimoides

4

a

Tail short, conoid or digitate

Shamimonema

b

Tail elongate, conoid or long, filiform

5

5

a

Tail elongate, conoid, ventrally arcuate

Arcidorylaimoides

b

Tail elongate, conoid, bent dorsally or long, filiform

Tarjania

Subamily Calolaiminae Goseco, Ferris and Ferris, 1976

1

a

Tail dissimilar in both sexes; odontophore strongly sclerotized

Miranema

b

Tail similar in both sexes; odontophore not strongly sclerotized

2

2

a

Odontostyle and guiding ring very thick; esophageal bulb long, cylindroid

Calolaimus

b

Odontostyle and guiding ring not very thick; esophageal bulb short, pyriform

Timmus

Family Aulolaimoididae Jairajpuri, 1964

1

a

Tail long and filiform

Aulolaimoides

b

Tail short and rounded

2

2

a

Pharyngeal structures present; female reproductive system monovarial, opisthodelphic

Adenolaimus

b

Pharyngeal structures absent; female reproductive system diovarial, amphidelphic

Oostenbrinckia

Suborder Nygolaimina Ahmad and Jairajpuri, 1979

Nygolaimoidea

Superfamily Nygolaimoidea Thorne, 1935

1

a

Basal expanded part of esophagus enclosed in a thick sheath of spiral muscles; female reproductive system monovarial, opisthodelphic

Nygellidae

b

Basal part of esophagus not enclosed in muscle sheath; female reproductive system diovarial, amphidelphic

2

2

a

Stoma sclerotized

Aetholaimidae

b

Stoma not sclerotized

3

3

a

Basal expanded part of esophagus about 1/2 esophagus length; cardiac glands present

Nygolaimidae

b

Basal expanded part of esophagus about 2/3 esophagus length, bibulbar; cardiac disk present

Nygolaimellidae

Family Nygolaimidae Thorne, 1935

1

a

Mural tooth deltoid to linear or dorylaimoid

Nygolaiminae

b

Mural tooth solid or acicular

Solididentinae