Table 3 Counts and measurements of Protobenthophilus squamatus n.gen. et sp. and comparison with the extant Caspiosoma caspium (Kessler 1877) and the aggregated extant genus Benthophilus (extant data after Ahnelt et al. 2000; Ahnelt 2003 and Miller 2004)

SL (mm)

18.9

<46

<94

Otolith in situ

Yes

Meristics

 Precaudal vertebrae

10

10

9–10

 Total vertebrae

28

27–29

27–31

 D 1

V

VI (V–VII)

II–IV

 D 2

I + 8

I + 10–13

I + 6–10

 A

I + 8

I + 7–10

I + 5–9

 Pectoral

6+

18–19

15–19

 D1 last ray between NS

NS5–NS6

NS6–NS7

NS4–5–NS5–6

 Empty neural spines

NS6–NS8

NS7–NS8

NS6–7–NS7–8

 D2 first PT between NS

NS8–NS9

NS8–NS9

NS7–8–NS8–9

 Caudal principle

16

13–14

 Dorsal pterygiophore formula

3-221001

3-221101

3-22100 or 3-221*01*1*

 Anal PT1 opposite to

D2/2

D2/3

 postmaxillary process on PMX

Present

Present

Present

 EPU

1

1

1

 AP

2

?

1

 SOP anterior-ventral shape

Smooth

Hook–like

Smooth

Scales

 On head

Naked

Naked

Absent (enlarged ossicles)

 On body

Predorsal naked

Naked

Absent (enlarged ossicles)

 Type

Ctenoid

–

–

 Scales along lateral line

~27

–

–

 Scale size (mm)

~0.6

–

–

Morphometrics (% of SL)

 Head length

32.0

28.5–32

28–43

 Max. body height

18.8

14.5–20.5

14–30

 Orbit diameter

6.3

~7.5

~3

 D1 length

13.6

 A length

8.5

 PL = pectoral length

12.7

 Predorsal to D1

35.5

37–42

37–52

 Predorsal to D2

52.3

 Preanal

60.9

 Base of D1

6.8

 Base of D2

21.0

26–34.5

15–30

 Base of A

25.5

 Distance of D1 to D2

9.0