With the advent of ancient DNA, as well as other methods such as isotope analysis, destructive sampling of archaeofaunal remains has increased much faster than the effort to collect and curate them. While there has been considerable discussion regarding the ethics of destructive sampling and analysis of human remains, this dialogue has not extended to archaeofaunal material. Here we address this gap and discuss the ethical challenges surrounding destructive sampling of materials from archaeofaunal collections. We suggest ways of mitigating the negative aspects of destructive sampling and present step-by-step guidelines aimed at relevant stakeholders, including scientists, holding institutions and scientific journals. Our suggestions are in most cases easily implemented without significant increases in project costs, but with clear long-term benefits in the preservation and use of zooarchaeological material.

OBJECTIVE: Recent reports have validated the use of retrosigmoid approach extensions to deal with posterior fossa lesions extending laterally extracranially or superiorly into the petroclival areas. The purpose of our research is to describe the topographic retrosigmoid anatomy of the petrous pyramid and provide guidelines for neurovascular sparing drilling (hence for a functional petrosectomy), via this surgical route.
METHODS: Suprameatal and inframeatal retrosigmoid approach extensions were performed bilaterally in 6 specimens in the semisitting position. Topographic relationships of pertinent labyrinthine landmarks with evident posterolateral cranial base structures were measured by neuronavigation.
RESULTS: Excellent exposure of inframeatal/petroclival regions as well as of the extracranial posterior infratemporal area was achieved in all the specimens. In the inframeatal region, petrous bone drilling was limited by the labyrinth and the internal auditory canal superiorly and by the jugular bulb, the inferior petrosal sinus, and the lower cranial nerves inferiorly. The intrapetrous internal carotid artery represented the anterolateral limit. In the suprameatal area, the drilling was limited laterally by the labyrinth (i.e., by the posterior part of the superior semicircular canal, the upper part of the posterior semicircular canal, and the common crus). The internal auditory canal was the inferior limit, and the superior petrosal sinus and the trigeminal nerve limited the drilling superiorly. Multiple topographic relationships among key landmarks were quantified.
CONCLUSIONS: Knowledge of the topographic anatomy of the labyrinthine structures examined may be useful (combined with careful assessment of the preoperative imaging and with the use of neuronavigation and endoscopy) to accomplish a retrosigmoid neurovascular sparing petrosectomy.

The extended middle fossa approach to the cerebello-pontine angle was practiced in ten human temporal bones, and the topographical relations of essential structures were studied by exposure of the bony labyrinth. After identification of the greater superficial petrosal nerve and the grey line of the superior semicircular canal landmarks were defined in order to localize the vertical crest (Bill\'s bar), the ampulla of the superior semicircular canal, the intralabyrinthine part of the facial nerve, the cochlea, and the internal carotid artery. The advantages of the extended middle fossa approach for the preservation of the labyrinthine and cochlear structures together with the safe identification of the facial and cochleo-vestibular nerves are emphasized.