The nuclear ITS1-5.8S-ITS2 DNA region is studied for 29 specimens of Coscinodon from Eurasia, mostly from Russia, and 4 specimens from North America. The sequences were found to be much less variable than in two other genera of the Grimmiaceae, Grimmia and Schistidium. Coscinodon yukonensis Hastings was found to be rather widespread in Asia, despite never having been reported before in this continent, being erroneously treated as C. humilis Milde. European C. humilis is quite distinct molecularly from Asian C. yukonensis and forms a sister clade to C. cribrosus (Hedw.) Spruce. Some Asian populations of "C. cribrosus" were unresolved, being found outside the main clade formed by C. cribrosus and C. humilis. Coscinodon hartzii C.E.O. Jensen forms a basal grade to the rest of the species in the genus. Coscinodon pseudohartzii is described as a species new to science from Siberia. РезюмеИзучен участок ITS1-5.8S-ITS2 ядерной ДНК у 29 образцов рода Coscinodon из Евразии, б.ч. из России, и 4 образцов из Северной Америки. Последователь-ности оказались намного менее вариабельными по сравнению с таковыми у двух других родов Grimmiaceae, Grimmia и Schistidium. Coscinodon yukonensis Hastings ранее не был отмечен в Азии, ранее образцы этого вида с этого континента относили к C. humilis Milde. Типичный C. humilis из Европы, однако, молекулярно отличается от него очень сильно и в то же время более близок к C. cribrosus (Hedw.) Spruce. Европейские и часть азиатских популяций C. cribrosus образуют кладу, сестринскую C. humilis, но ряд азиатских популяций "C. cribrosus" оказывается в неразрешенном положении. Coscinodon hartzii C.E.O. Jensen образует граду в основании дерева рода. По результатам анализа в Сибири выявлен не описанный ранее вид, C. pseudohartzii.

Behavioural innovations with tool-like objects in non-habitually tool-using species are thought to require complex physical understanding, but the underlying cognitive processes remain poorly understood. A few parrot species are capable of innovating tool-use and borderline tool-use behaviours. We tested this capacity in two species of macaw (Ara ambiguus, n = 9; Ara glaucogularis, n = 8) to investigate if they could solve a problem-solving task through manufacture of a multi-stone construction. Specifically, after having functional experience with a pre-inserted stick tool to push a reward out of a horizontal tube, the subjects were required to insert five stones consecutively from one side to perform the same function as the stick tool with the resulting multi-component construction. One Ara glaucogularis solved the task and innovated the stone construction after the experience with the stick tool. Two more subjects (one of each species) did so after having further functional experience of a single stone pushing a reward out of a shortened tube. These subjects were able to consistently solve the task, but often made errors, for example counter-productive stone insertions from the opposing end, even in some of the successful trials. Conversely, multiple trials without errors also suggested a strong goal direction. Their performance in the follow-up tasks was inconclusive since they sometimes inserted stones into un-baited or blocked ‘dummy tubes’, but this could have been an attention-deficit behaviour as subjects had not encountered these ‘dummy tubes’ before. Overall, the successful subjects’ performance was so erratic that it proved difficult to conclude whether they had functional understanding of their multi-stone constructions.

Causal understanding in animal cognition can be divided into two broad categories (Woodward, 2011): learned associations between cause and effect (Le Pelley et al., 2017) and understanding based on underlying mechanisms (Johnson and Ahn, 2017). One experiment that gives insight to animals’ use of causal mechanisms is the stone-dropping task. In this, subjects are given an opportunity to push a platform to make it collapse and are then required to innovate dropping a stone tool to recreate the platform collapsing (von Bayern et al., 2009). We describe how 16/18 subjects of two species of macaw (n=18; Ara ambiguus (n=9) & Ara glaucogularis (n=9)) were able to innovate the solution in this task. Many of the subjects were able to innovate the behaviour through exploratory object combination, but it is also possible that a mechanistic understanding of the necessity for contact with the platform influenced some subjects’ behaviour. All the successful subjects were able to recreate their novel stone-dropping behaviour in the first or second trial after innovation (and all trials thereafter) and they were also able to do the behaviour increasingly faster. This suggests they also rely on learned associations of cause and effect. However, in a transfer task in which subjects had to guide a stick tool to make it touch a differently positioned platform, all but one of the subjects failed. This would suggest that the majority of the subjects were not using an understanding of platform contact to solve the task, although the subjects’ difficulty with using stick tools may have also affected their performance in this transfer.