|
Cesare Brizio's collection of Oliva Shells
Provisional web page Version 24.0 (5 November 2023)
No. of specimens figured: around 1260
CLICK HERE FOR IMAGES
This page was automatically generated from an Excel spreadsheet and will be improved in the future.
Its only aim is to make available to other collectors medium quality, recognizable pictures of every specimen in my Oliva shells collection.
No search feature is available apart the Ctrl-F feature provided by most browsers.
I'm well aware that the systematics of Olives is in constant evolution, and I'm in the process of improving my competence.
So please use this page only for its declared purpose: allowing you to check how my specimens look like.
Please don't use it to validate your specific determinations: although well advised by competent olivologists, I have no authority in that respect and the determinations provided in this page should all be regarded as tentative.
Errors are mine, not of my advisors.
You may freely download and improve the pictures for your personal use.
Among the known issues of this page:
- the Authors listed as sources for each species may be inaccurate;
- (sub)genera of the genus Oliva (full genera, according to some scholars) are quite well established in literature, I still prefer to stick to the single genus Oliva and specify the (sub)genus in round brackets;
- photographs are in alphabetical order of species name;
- the two thumbnails provided for each specimen may differ in height: this is due to the fact that each picture may have a different H/W ratio, and all the thumbnails were normalized at 200px width;
- the exposure of the two views of each specimen may vary significantly, as long as almost invariably the apertural side is much more reflective than the dorsal side - so, the darker pictures are not to be considered faulty;
- table row height is determined by the tallest thumbnail - and this gives a disordered appearance to the whole table;
- the full size pictures were cropped from 8MP originals. The whole process of digital photography adopted for this collection is described in this report;
- the table itself may format suboptimally, depending on your browser: it was automatically generated by an excel spreadsheet and will require refinements in the future;
- the pictures serve solely for the purpose to allow specimen and species recognition and were obtained with a compromisory "one shot per specimen" approach, conceived to minimize the time required for this massive effort of digital imaging: feel free to contact me on Facebook or on Google if you need better quality pictures;
- Locality names are in Italian - "Località sconosciuta" means "Unknown locality", and other Italian words may emerge here and there.
Notes on taxonomy
Like any zoological group of interest, the olivological community is stirred by many debates, many of which several decades old.
For the sake of simplicity and to improve ease of identification and comparison with the specimens by other owners, I will stick to the following simple rules:
- It's well known that - unless they are described as regular subspecies - «forms» and «varieties» have no official taxonomic standing, and that on the contrary they may be misleading. This notwithstanding, their usage is so widespread that I elected to keep it. Forms, when present, are listed in alphabetical order under each species;
- The status of subgenera and their erection to proper genera is still a cause of controversies within the scientific community. In particular before the "Atlas" by Petuch and Sargent, subgenera were often loosely defined and used differently by each author. The new subgenera adopted by Petuch and Sargent where not universally accepted in subsequent olivological publication. Now, even though there are good reasons to consider genera such as Americoliva, Miniaceoliva and Viduoliva as valid, an exhaustive overview of those taxonomic entities is sorely needed, particularly regarding their definition, as well as an updated list of the species belonging in each "new" genus - a task made difficult by nomenclatural issues. For all those reasons, I'll keep referring generally to the Oliva genus, even though it's ascertained that it may be a lump of more than one genus;
- Regardless of my (low) degree of experience and of my (poor) standing as an olivologist, I reserve the right to have an opinion. So, in many situations, I refused to accept nomenclatural acts that in my opinion are not adequately justified. In that respect, the retention of old taxon names in the list that follows may be caused by ignorance (e.g. I missed a paper with some taxonomical novelty) or by refusal (e.g. I read the paper but it didn't convince me), but most often by the fact that I side with one of my competent advisors, whose judgement I trust more than my own.
|
