Tiraɣlalin (Assaɣ ussnan: Invertebrata) d irem i d-issemsel umesnudran Afrensaw (Jean-Baptiste Lamarck) i wakken ad iglem iɣersiwen ur nli ara (ur nesɛi ara) ajgu n uzagur. Imalla tagrawt-a d tin igebbren yakk iɣersiwen anagar tinaɣlalin (Iselman, Timraradin, Tikelmanin, Igṭaṭ d temsuṭaṭ) Imusnawen n tesnudert ggunin deg beṭṭu n iɣersiwen-a ɣef waṭas n yisefka, am: tmerwest, amruj afekkan d tissiwin timessiruwin Tigti n imuddiren Agzam d beṭṭu Timerwest: imesnudranen bṭan imuddiren ɣer tsendisin (Bilateria) d timmardisin (Radiata) ma d talmest taneggart d tirmarwasin (Asymmetry). Tiraɣalil sgensisent-d azal n 97% n yiɣersiwen yellan deg umadal Asesmel Tiswermin Ẓeṛ daɣen Tinaɣlalin == Imniren ==