Damsel Field Guide
Dragon Field Guide
Sapphire Rockmaster
Orange Threadtail
Coastal Petaltail
Unicorn Darner
Coastal Evening Darner 


Tau Emerald Dragonfly - Hemicordulia tau


This page contains information and pictures about Tau Emerald Dragonflies that we found in the Brisbane area, Queensland, Australia. They are also known as T-Mark Emeralds.

Body length 50mm

The Tau Emerald Dragonflies are medium in size. They look very similar to another Emerald species Australian Emerald but they do not have the metallic green colour on their head. They can be found in the same habitat. Because both of them never rest, it is difficult to distinguish between them in the field. Anyway, the Tau Emeralds are less common in Brisbane. 

Take a closer look of the dragonfly's face. There is the inverse black 'T' mark on its 'nose'. This is why those dragonflies are call T-Mark Emerald. Some other dragonflies also have the inverse 'T' mark on their face, such as the Yellow Emperor dragonflies. The T-mark is also the easy way to distinguish them from  Australian Emerald. Australian Emeralds has their face black with metallic blue-green reflections. 
Like all members in this dragonfly family, when perched, they usually hang suspended vertically. They rest high on trees at night.
The T-Mark Emerald Dragonfly has two pair of wings which are about equal in size. They are clean in colour. It veins pattern are the same as Australian Emerald but veins colour is yellow brown, while the Australian Emerald is black in colour.

1. The Australian Dragonflies - CSIRO, Watson, Theisinger & Abbey,1991, p220.
2. A Field Guide to Dragonflies of South East Queensland - Ric Nattrass, 2006, p80.
3. The Complete Field Guide to Dragonflies of Australia - CSIRO, GŁnther Theischinger and John Hawking, 2006, p248.

Back to Top

Up ] Australian Emerald ] Fat-bellied Emerald ] [ Tau Emerald ]


See us in our Home page. Download large pictures in our Wallpaper web page. Give us comments in our Blog, or send email to us. A great way to support us is to buy the CD from us.  
Last updated: May 12, 2007.