Reconstructions

PWS
*ŝir- - skin, hide of cattle (SED I No. 267)

A very complicated and problematic case. It is difficult ot say whether the Soq. ans S. Eth. parallels preserve an original biconsonantal stem, with ˁ (or ˀ) added later as a triconsonantizer (*ŝrˁ) or they have lost the original laryngeal in the position of the second or third radical. As an anatomic term attested in M. Eth. and Soq. only. Cf. *ŝry - to skin. 

PWS
*ŝrˁ - to set in order (Kogan 2015: 221)
PWS
*ŝawk-/*ŝVkk- - thorn (Kogan 2015: 579; CDG 529)
PWS
*ṣ̂aˀl- - zizyphus (Blau 1971b:5‒8)
PWS
*ṣ̂abb- - monitor lizard (SED II No. 221; Kogan 2011: 211)
PWS
*ṣ̂ḥk/ṣ̂ḥḳ - to laugh (SED I 70ᵥ)
The level of reconstruction is uncertain due to semantic difficulties concerning the possible Akkadian cognate.
PWS
*ṣ̂amr- - wool, fleece (Kogan 2015: 122)
conspicuously missing from Arabic
PWS
*ṣ̂pr - to plait (Kogan 2015: 98)
PWS
*ṣ̂Vpˁ- - dung (SED I No. 273; Kogan 2011: 227)
PWS
*ṣ̂VpardVˁ- - frog (SED II No. 222; Kogan 2011: 210)
It is only the Hbr. form that reflects the original quinqueconsonantal base, reduced to *ṣ̂VrdVˁ- in Aramaic and *ṣ̂VpdVˁ- in Arabic and MSA. Alternatively, two unrelated quadriconsonantal terms can be postulated for PS with their subsequent contamination in Hebrew.