Hi Zhang, 

In my opinion, this fauna consists of non-marine ostracods. Please see below:

Figure 2. Candonidae family (?Candona sp.)

Figure 9. Limnocytheridae family (Limnocythere sp.-Female)

Figure 15. Limnocytheridae family (Limnocythere sp.-Male)

Figure 18. Ilyocyprididae family (Ilyocypris sp.)

For species-level determination, we need to have more SEM images (dorsal and internal view of valves etc.)

Best regards...

Alaettin

Hi Zhang,

First of all you should tell some thing about the environment of these species. Are they from marine, brackish water, or freshwater environment? Moreover you have to take SEM from inner side of the carapaces too. On the bases of the provided photographs, the first one is Candona sp. and the last one is most likely Ilyocypris bradyi, needs to see the inner features too. The other two species, as Alaettin comments, are looking to limnocytheresp., but need to be confirmed about their environment.

Cheers,

Habib.

Hi Zhang,

I agree with Alaettin: these specimens are non-marine, freshwater ostracods.

fig 2 Candona (close to Fabaeformiscandona)

fig 9+15 Limnocythere sp.

fig 18 Ilyocypris bradyi

If you want to identify the exact species, you have to examine:

left and right carapaces

male and female specimens

and inner side of carapaces , too.

Best regards:

Andrea

Fresh to brackish water species.  Need more morphological data for a precise ID.

Dear Alaettin, Habib, Andrea and Schafer,

Thank you for helping me.  they were all found in the lake sediment.

I just can provide the inner side SEM image of  Fig.18, as I didi not have SEM image of others..

Best wishes

Now, i would say fig.53 and fig.18 can be named as Ilyocypris bradyi. Species-level determinations of the genus Ilyocypris is complicated. However if you compare fig 53. with Mazzini et al. (2014), p. 399, fig. 2c, you will notice that form (in fig. 53) is belonged to Ilyocypris bradyi. 

Regards,

Alaettin

Hi Zhang,

Fig.9 looks like Leguminocythereis sorneana

All the best

Hakima