On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence.
A spectacular hypothesis was published recently, which suggested that the "helmet" (a dorsal thoracic sclerite that obscures most of the body) of treehoppers (Insecta: Hemiptera: Membracidae) is connected to the 1st thoracic segment (T1; prothorax) via a jointed articulation and therefore...
Main Authors: | , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Public Library of Science (PLoS)
2012-01-01
|
Series: | PLoS ONE |
Online Access: | http://europepmc.org/articles/PMC3260216?pdf=render |
id |
doaj-f60a3cdd4c07442c8d9c0985d6623af1 |
---|---|
record_format |
Article |
spelling |
doaj-f60a3cdd4c07442c8d9c0985d6623af12020-11-25T01:38:39ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0171e3013710.1371/journal.pone.0030137On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence.István MikóFrank FriedrichMatthew J YoderHeather M HinesLewis L DeitzMatthew A BertoneKatja C SeltmannMatthew S WallaceAndrew R DeansA spectacular hypothesis was published recently, which suggested that the "helmet" (a dorsal thoracic sclerite that obscures most of the body) of treehoppers (Insecta: Hemiptera: Membracidae) is connected to the 1st thoracic segment (T1; prothorax) via a jointed articulation and therefore was a true appendage. Furthermore, the "helmet" was interpreted to share multiple characteristics with wings, which in extant pterygote insects are present only on the 2nd (T2) and 3rd (T3) thoracic segments. In this context, the "helmet" could be considered an evolutionary novelty. Although multiple lines of morphological evidence putatively supported the "helmet"-wing homology, the relationship of the "helmet" to other thoracic sclerites and muscles remained unclear. Our observations of exemplar thoraces of 10 hemipteran families reveal multiple misinterpretations relevant to the "helmet"-wing homology hypothesis as originally conceived: 1) the "helmet" actually represents T1 (excluding the fore legs); 2) the "T1 tergum" is actually the anterior dorsal area of T2; 3) the putative articulation between the "helmet" and T1 is actually the articulation between T1 and T2. We conclude that there is no dorsal, articulated appendage on the membracid T1. Although the posterior, flattened, cuticular evagination (PFE) of the membracid T1 does share structural and genetic attributes with wings, the PFE is actually widely distributed across Hemiptera. Hence, the presence of this structure in Membracidae is not an evolutionary novelty for this clade. We discuss this new interpretation of the membracid T1 and the challenges of interpreting and representing morphological data more broadly. We acknowledge that the lack of data standards for morphology is a contributing factor to misinterpreted results and offer an example for how one can reduce ambiguity in morphology by referencing anatomical concepts in published ontologies.http://europepmc.org/articles/PMC3260216?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
István Mikó Frank Friedrich Matthew J Yoder Heather M Hines Lewis L Deitz Matthew A Bertone Katja C Seltmann Matthew S Wallace Andrew R Deans |
spellingShingle |
István Mikó Frank Friedrich Matthew J Yoder Heather M Hines Lewis L Deitz Matthew A Bertone Katja C Seltmann Matthew S Wallace Andrew R Deans On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence. PLoS ONE |
author_facet |
István Mikó Frank Friedrich Matthew J Yoder Heather M Hines Lewis L Deitz Matthew A Bertone Katja C Seltmann Matthew S Wallace Andrew R Deans |
author_sort |
István Mikó |
title |
On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence. |
title_short |
On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence. |
title_full |
On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence. |
title_fullStr |
On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence. |
title_full_unstemmed |
On dorsal prothoracic appendages in treehoppers (Hemiptera: Membracidae) and the nature of morphological evidence. |
title_sort |
on dorsal prothoracic appendages in treehoppers (hemiptera: membracidae) and the nature of morphological evidence. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2012-01-01 |
description |
A spectacular hypothesis was published recently, which suggested that the "helmet" (a dorsal thoracic sclerite that obscures most of the body) of treehoppers (Insecta: Hemiptera: Membracidae) is connected to the 1st thoracic segment (T1; prothorax) via a jointed articulation and therefore was a true appendage. Furthermore, the "helmet" was interpreted to share multiple characteristics with wings, which in extant pterygote insects are present only on the 2nd (T2) and 3rd (T3) thoracic segments. In this context, the "helmet" could be considered an evolutionary novelty. Although multiple lines of morphological evidence putatively supported the "helmet"-wing homology, the relationship of the "helmet" to other thoracic sclerites and muscles remained unclear. Our observations of exemplar thoraces of 10 hemipteran families reveal multiple misinterpretations relevant to the "helmet"-wing homology hypothesis as originally conceived: 1) the "helmet" actually represents T1 (excluding the fore legs); 2) the "T1 tergum" is actually the anterior dorsal area of T2; 3) the putative articulation between the "helmet" and T1 is actually the articulation between T1 and T2. We conclude that there is no dorsal, articulated appendage on the membracid T1. Although the posterior, flattened, cuticular evagination (PFE) of the membracid T1 does share structural and genetic attributes with wings, the PFE is actually widely distributed across Hemiptera. Hence, the presence of this structure in Membracidae is not an evolutionary novelty for this clade. We discuss this new interpretation of the membracid T1 and the challenges of interpreting and representing morphological data more broadly. We acknowledge that the lack of data standards for morphology is a contributing factor to misinterpreted results and offer an example for how one can reduce ambiguity in morphology by referencing anatomical concepts in published ontologies. |
url |
http://europepmc.org/articles/PMC3260216?pdf=render |
work_keys_str_mv |
AT istvanmiko ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT frankfriedrich ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT matthewjyoder ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT heathermhines ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT lewisldeitz ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT matthewabertone ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT katjacseltmann ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT matthewswallace ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence AT andrewrdeans ondorsalprothoracicappendagesintreehoppershemipteramembracidaeandthenatureofmorphologicalevidence |
_version_ |
1725052377161007104 |