Table 1 Data available prior to this study on the musculature of Loricifera

Nanaloricus mysticus

TEM

8 (inside the ridges)

16 (attached to the furcal base)

5 inner and 15–24 outer

2-3 (surrounding the brain)

6 buccal tube retractors; spinoscalid muscles; 10 rings (scalid rows)

(nd)

(nd) ^a)

myoepithelial, radial musculature

[12, 20, 21]

Armorloricus elegans*

TEM, LM

(np)

(np)

6 inner and at least 15 outer; 1 dorsal pair spans through the whole body (widely separated)

1 (surrounding the brain)

spinoscalid muscles

1 dorsal pair (same fiber that runs in the introvert)

several diagonal and dorso-ventral muscles

myoepithelial, radial musculature

[2, 12, 25]

Pliciloricus enigmaticus

TEM

8 (inside the ridges)

16 (attached to the furcal base)

5 inner and 15–24 outer

2-3 (surrounding the brain)

spinoscalid muscles; scalid ring muscles^b)

20-22

11 (ring-like)

myoepithelial, radial musculature

[20]

Pliciloricus pedicularis

LM

8 (run through the brain)

−

1 pair large; neighbor retractors present (smaller)

1 (ring-like)

spinoscalid large diagonal muscles

several (located anteriorly)

several transverse muscles; 1 (ring-like, posterior)

3 transversal layers of radial muscles

[10]

Pliciloricus diva

LM

8 (run through the brain)

−

1 pair large; neighbor retractors present (smaller)

−^c)

spinoscalid diagonal muscles; scalid ring muscles

several (located anteriorly)

3 layers of transverse muscles;

(nd)

[11]

Rugiloricus doliolius

LM

8 (run through the brain)

−

1 dorsal pair (large)

− ^c)

spinoscalid muscles; scalid ring muscles

several bundles

many bundles (ring muscles)

(nd)

[16, 26]

Rugiloricus renaudae

LM

present

−

present

present

spinoscalid muscles

several strings

narrow bundles (transverse)

(nd)

[13]

Pliciloricus pedicularis

LM

−

−

−

−

−

several

several (transverse)

muscles arranged in five layers of 3 radial muscles

[10]

Pliciloricus diva

LM

−

−

−

−

−

−

−

muscles arranged in five layers of 3 radial muscles

[11]

Rugiloricus doliolius

LM

6 short

−

8

− ^c)

spinoscalid muscles

8 (ventral pair strongest); toe base muscles

7 ring muscles

(nd)

[16, 26]