Infructescences of Cathiaria gen. n. from the late Cretaceous North Kazakhstan and Siberia (Russia)

We used infructescences from the late Cretaceous deposits of northern Kazakhstan and Siberia to establish Cathiaria gen. n. These infructescences are compound, consisting of two orders of axes: a main axis that is irregularly finely ribbed, and alternate to subopposite secondary lateral axes. Immature lateral axes are short, flattened, and bract-like; they bear sessile fruits on the adaxial side. During maturation the lateral axes become elongated, more or less cylindrical, bearing nutlet-like, single-seeded fruits. The systematic position of Cathiaria is uncertain. Among the recent plant taxa this genus shares most features with the family Moraceae. The infructescences of Cathiaria have been found in association with the leaves of Liriodendropsis simplex (Newb.) Newb. in six localities and in association with the male inflorescences of Freyantha sibirica Krassilov & Golovneva at one locality. Here we present evidence to support the hypothesis that these organs may have been produced by the same plant, presenting an unusual combination of characters suggestive of an extinct angiosperm family.