The fossil record of exceptionally preserved soft tissues in Konservat-Lagerstätten provides rare yet significant insight into past behaviours and ecologies. Such deposits are known to occur in bursts rather than evenly through time, but reasons for this pattern and implications for the origins of novel structures remain unclear. Previous assessments of these records focused on marine environments preserving chemically heterogeneous tissues from across animals. Here, we investigate the preservation of skin and keratinous integumentary structures in land-dwelling vertebrates (tetrapods) through time, and in distinct terrestrial and marine depositional environments. We also evaluate previously proposed biotic and abiotic controls on the distribution of 143 tetrapod Konservat-Lagerstätten from the Permian to the Pleistocene in a multivariate framework. Gap analyses taking into account sampling intensity and distribution indicate that feathers probably evolved close to their first appearance in the fossil record. By contrast, hair and archosaur filaments are weakly sampled (five times less common than feathers), and their origins may significantly pre-date earliest known occurrences in the fossil record. This work suggests that among-integument variation in preservation can bias the reconstructed first origins of integumentary novelties and has implications for predicting where, and in what depositional environments, to expect further discoveries of exquisitely preserved tetrapod integument.

The fossil record of exceptionally preserved soft tissues in Konservat-Lagerstätten provides rare yet significant insight into past behaviours and ecologies. Such deposits are known to occur in bursts rather than evenly through time, but reasons for this pattern and implications for the origins of novel structures remain unclear. Previous assessments of these records focused on marine environments preserving chemically heterogeneous tissues from across animals. Here, we investigate the preservation of skin and keratinous integumentary structures in land-dwelling vertebrates (tetrapods) through time, and in distinct terrestrial and marine depositional environments. We also evaluate previously proposed biotic and abiotic controls on the distribution of 143 tetrapod Konservat-Lagerstätten from the Permian to the Pleistocene in a multivariate framework. Gap analyses taking into account sampling intensity and distribution indicate that feathers probably evolved close to their first appearance in the fossil record. By contrast, hair and archosaur filaments are weakly sampled (five times less common than feathers), and their origins may significantly pre-date earliest known occurrences in the fossil record. This work suggests that among-integument variation in preservation can bias the reconstructed first origins of integumentary novelties and has implications for predicting where, and in what depositional environments, to expect further discoveries of exquisitely preserved tetrapod integument.

Background: Electroencephalography (EEG) -based motor-imagery brain-computer interface (MI-BCI) systems can facilitate training of wilful modulation of sensorimotor oscillations in patients with prolonged disorders of consciousness, potentially enabling empirical assessment of awareness and movement independent responses and question answering. Methods: A multistage, ten session, protocol was evaluated with twenty-four (N = 24) patients who have prolonged disorders of consciousness (PDoC) (unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS)) or locked-in syndrome (LIS). Phase one assessed capacity to modulate brain activity and thus detect awareness, phase two involved motor-imagery training with neurofeedback, and phase three assessed patients’ motor-imagery response to closed questions, categorised to assess biographical, numerical, logical, and situational awareness. Results: Patients from all groups show significant capacity to modulate brain activity and respond to closed questions with motor imagery. A conservative approach to statistical testing was necessarily taken, due to a limited sample size and uneven groups. However, significant group differences were observed indicating patients with LIS outperform patients with PDoC. As patients diagnosed with UWS present evidence of command following in this protocol and thus could have MCS, significant differences between UWS and MCS across a range of tests were inconclusive although, in general, group performances are correlated with the level of awareness associated with clinical diagnosis. Conclusions: We conclude that the proposed multistage protocol involving progression from motor imagery training with neurofeedback to closed question responses under the correct conditions may be effective for movement-independent consciousness profiling in prolonged disorders of consciousness.