Hi Filiberto,
The number of extant ‘Crivelli» 15th century rugs is apparently a bit larger than what I thought initially.
With two additional ones below:
The whereabouts of the first one are unknown to me. The latter one is a large fragment, of which a computer reconstitution of the central medallion is shown here, which belongs to the Kirchheim collection (Orient Stars, page 275).
These (painted or extant) Crivelli rugs show an interesting evolution of an animal motif from figurative to abstraction beyond recognition. The departure from naturalistic representation might have been caused, for example, by a stricter (local or temporary) enforcement of Islam’s ban of human and animal motifs.
Another interesting point is the particular type of border of the first rug: A motif which has survived without change over a millenary, since it was already featured in the large carpet of the early fourteenth century miniature below (1330-1340, Il-khanid period, Tabriz school, "The bier of Iskander". Freer Gallery, Smithsonian ) and was still rather frequent in nineteenth century Caucasian rugs.
Best
Pierre