Using the TMT key
The identification process
The keying process is complete when there is only a single selection remaining. Selecting additional characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states at this point will prove to be futile as there will be no other taxa to discard. If the selection is not satisfactory, the organism can be taken through the key again, this time using other characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states. Also the final selection may not be identical (color and markings) to the specimen in hand, as many gastropodGastropod:
A single-shelled mollusc.
species are morphologically variable. It is therefore recommended that the user read the fact sheetFact sheet:
1). A presentation of data in an HTML format on any subject emphasizing brevity, key points of interest or concern, and a way to convey the most relevant information in the least amount of space; 2). An HTML page itemizing the facts or pertinent information about each of a tool's entities.
on the final selection to confirm the identification as additional information, including pictures, are provided in this section of the tool.
Selecting characters
One important featureFeature:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 3 interactive matrix panel. (compare character)
of a Lucid key is the flexibility it provides the user to choose morphological characters pertinent to the specimen in question in any order and in any combination. The user is however advised to select obvious characters first before progressing to more obscure characters. Additionally, multiple characters may be selected simultaneously, and unclear characters and those difficult to determine may be skipped.
Measurable characters such as heightHeight:
The height of the shell is a measure of the distance between the apex and the most basal part of the shell OR the measurement taken from the apex of the shell to the base, when measured parallel to the axis of the shell.
, widthWidth:
The width of the shell is the maximum distance across the shell (including the aperture).
, length, number of whorlsWhorls:
Pleural of whorl. A whorl is a complete spiral turn/growth of the shell of a mollusc. The whorls are counted from the apex outwards.
etc, are very useful to quickly reduce the number of “Entities Remaining”. It is therefore extremely important to correctly measure the specimen in question. The user should consult the Identification page for the correct procedures to measure terrestrial gastropods. Do not estimate measurable characters or guess any other characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
selections. When in doubt choose alternative characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states.
Dissections and comparing genitalia
Several entitiesEntities:
See also entity
included in this key cannot be reliably identified using external morphological characters. Additionally, some entitiesEntities:
See also entity
may be grouped in a species complex and require examination of genital structures for correct identification. If the specimen in question falls into the aforementioned categories and identification to a lower taxonomic level is desired, the user has several options. The user could send the specimen to an expert for official identification. OR Based on skill level and appetite for adventure the user may choose to dissect the specimen in question in order to inspect the genitaliaGenitalia:
The reproductive structures of an animal. May refer to either male or female structure.
. The user should consult the dissection page for the supplies required and the procedures for correctly and humanely preparing the specimen. The slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
and snail dissection tutorials provide a step-by-step guide to the dissection process. The specimen in question may be quite different from those used in the tutorials, but the principles are the same. The fact sheets provide detailed illustrations of characteristic genitalic structures required for identification of entitiesEntities:
See also entity
to the species level. The dissected genitaliaGenitalia:
The reproductive structures of an animal. May refer to either male or female structure.
of the unidentified specimen should be compared to pertinent illustrations in order to make a determination.
Entity not in key
It is probable that on occasions the end-user will be unable to make an appropriate final selection on the first attempt to key a specimen. The end-user would be advised to attempt to ‘re-key’ the specimen by selecting a different suite of characters or by selecting the “magic wand” featureFeature:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 3 interactive matrix panel. (compare character)
after the dependency characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
, within the key. If no selection can be made after a reasonable number of attempts, the user must consider the possibility that the specimens on hand may be a species not included in the key. Additionally, the specimen may be a juvenile, the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
may be severely weathered (snails), or the specimen may be an albino morph and therefore lack the characters required to make a final selection.
Multiple entities remain
The occasion may arise where the user has exhausted all possible selections from the “Features available” quadrant of the key window yet multiple entitiesEntities:
See also entity
remain in the “Entities Remaining” quadrant. The most likely explanation is that the specimen in question is not an entityEntity:
In Lucid, entities are the items the key aims to identify. Lucid uses the term entity to encompass items of all types.
included in the key. There may also be occasions where multiple entitiesEntities:
See also entity
remain in the “Entities Remaining” quadrant of the key window and multiple characters remain in the “Characters Remaining” quadrant, but none of the remaining features are pertinent to the specimen in question. In such a case, it is possible that the specimen in question could be a juvenile and lack the characters required for identification or may be an entityEntity:
In Lucid, entities are the items the key aims to identify. Lucid uses the term entity to encompass items of all types.
not included in the key.
All remaning entities disappear
There may be occasions when the selection of a particular suite of characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states result in all entitiesEntities:
See also entity
disappearing from the “Entities Remaining” quadrant of the key window. In such a case no entityEntity:
In Lucid, entities are the items the key aims to identify. Lucid uses the term entity to encompass items of all types.
in the key has been scored for the combination of characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states selected. This could be attributed to a number of reasons including user-error in selecting appropriate characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states or the specimen in question may not be included in the key. The user may attempt to discover a potential error by sequentially de-selecting all dubious characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states. The “Entities Remaining” quadrant may re-populate as characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states are removed from the “Features Chosen” list. Carefully re-examine the specimen in question and only choose features and characterCharacter:
1). A distinctive trait, quality or attribute used for recognizing, describing, or differentiating taxa; 2). The term used to denote such descriptive traits that possess states and are located within the Lucid version 2 (and later) interactive matrix panel. (compare feature)
states that can be selected with confidence. If all entitiesEntities:
See also entity
continue to disappear from the “Entities Remaining” quadrant after several attempts using different combinations of features and states then it is most likely that the specimen in question is not included in the key. Please remember that this key is limited to identifying only the species included.