In an attempt to clarify the relationships of the Fringillidae and allied groups, I here review briefly the evidence which has been presented. From his studies of jaw-musculature (1951a, 1951b, 1953) Beecher concludes that the Pyrrhuloxinae (=Richmondeninae), the Carduelinae, and the Thraupinae are closely related. He places these groups in the Family Thraupidae. He excludes the Emberizinae from this group and places them with the wood warblers in the Family Parulidae. He suggests that the estrildines constitute a family (Estrildidae) separate from the Family Ploceidae.
From his studies of certain features of the bony palate Tordoff (1954:25-26, 32) concludes that the richmondenines, the emberizines, and the tanagers have a common origin and places these groups in the Family Fringillidae. He excludes the carduelines from this assemblage, suggests that they are closely related to the estrildines, and includes them as the Subfamily Carduelinae in the Family Ploceidae.
In this paper I have presented data obtained from the study of certain features of morphology and biochemistry which I think are less subject to the influence of environmental factors than those features studied by recent workers. It is significant that the data obtained by use of serological techniques and those obtained from the study of leg-musculature point to the same conclusions. On the basis of these data I have drawn several conclusions concerning the relationships of the groups which I studied.
The richmondenines, emberizines, and tanagers are closely related and should be included in a single family, Fringillidae. The Carduelinae and the Estrildinae are closely related subfamilies. Although most recent classifications place the Estrildinae and Passerinae in the Family Ploceidae, the serological evidence indicates that these groups are not closely related. Beecher (1953:303-304) drew the same conclusion from his study of jaw-musculature (see above). I suggest, therefore, that the Carduelinae and the Estrildinae be placed in a family separate from the Ploceidae and that the name Carduelidae (rather than Estrildidae) be used for this group. At present, neither is an accepted family name. Because Carduelis Brisson 1760 is an older name than Estrilda Swainson 1827 and because Carduelis seems to be a centrally located genus in the family, I have chosen the former (although the International Rules of Zoological Nomenclature do not specify that priority must apply in forming family names).
I have been unable to study any of the species included in the subfamilies Fringillinae (not Fringillinae of Tordoff, see 1954:23-24, and below) and Geospizinae of recent classifications; thus these groups have not been discussed above. Beecher (1953:307-308) includes Fringilla in the Subfamily Carduelinae; he includes the geospizines in a separate family, Geospizidae, and states that they are derived from the emberizines. Tordoff (1954:23-24) found that in features of the bony palate Fringilla and the geospizines resemble the emberizines and, on this basis, includes them in the Subfamily Fringillinae.
The Dickcissel, Spiza americana, possesses certain features which merit special discussion. Beecher (1951a:431; 1953:309), on the basis of jaw-musculature, considers it an icterid. To be sure Spiza is in many ways an aberrant member of the group to which it is now assigned (Subfamily Richmondeninae). Spiza, serologically, is closely related to all species of the richmondenine-emberizine-thraupid assemblage. Within this assemblage its nearest relatives are the richmondenines. Spiza differs from the other richmondenines studied and resembles the emberizines and tanagers in the possession of the muscular band which extends from the pars interna of the m. gastrocnemius around the front of the knee. This band, in Spiza, is smaller, however, than in any of the other species. No icterid dissected possesses such a structure. Tordoff (1954:29) states that Spiza is typically richmondenine in palatal structure and makes the suggestion, with which I agree, that Spiza is a richmondenine and may be closely related to the ancestral stock which gave rise to the fringillid assemblage. The serological position of Spiza, approximately equidistant from the other fringillids (Figs.[ 22],[ 23]), and the presence of the small muscular band around the front of the knee constitute evidence supporting the central position of Spiza.
After consideration of evidence from the studies of external morphology, ethology, myology, osteology, and serology, I propose here an arrangement of the groups which I have studied and submit for comparison the arrangements (of these groups) proposed by Beecher and Tordoff. The names of subfamilies that I have been unable to study are included in my classification and are placed in brackets.
| Here proposed | Proposed by Tordoff (1954) on the basis of the bony palate: | Proposed by Beecher (1953) on the basis of jaw-musculature: |
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| Family Ploceidae | Family Ploceidae | Family Ploceidae |
| [Subf. Bubalornithinae] | Subf. Bubalornithinae | |
| Subfamily Passerinae: distinguished from the Estrildinae by patterns of jaw-musculature (Beecher, 1953:303-304) and on the basis of comparative serology of saline-soluble proteins. | Subfamily Passerinae | Subfamily Passerinae |
| [Subfamily Ploceinae] | Subfamily Ploceinae | Subfamily Ploceinae |
| [Subfamily Viduinae] | Subfamily Viduinae | Subfamily Viduinae |
| | |
| Family Carduelidae | ||
| Subfamily Estrildinae: similar to the Carduelinae in features of the bony palate and habits (Tordoff, 1954: 18-22) and in patterns of leg-musculature and comparative serology of saline-soluble proteins. | Subfamily Estrildinae | Family Estrildidae |
| Subfamily Carduelinae: distinguished from the Fringillidae by features of the palate, geographic distribution, migration patterns, and habits (Tordoff, 1954: 14-18) and by patterns of leg-musculature and comparative serology of saline-soluble proteins. | Subfamily Carduelinae | [In Thraupidae below] |
| | |
| Family Fringillidae: all members of this family show similarities in features of the bony palate (Tordoff, 1954: 22-23), patterns of leg-musculature, and in comparative serology of saline-soluble proteins. | Family Fringillidae | Family Parulidae Subfamily Parulinae Subfamily Emberizinae |
| Family Thraupidae | ||
| Subf. Richmondeninae Subfamily Thraupinae Subfamily Emberizinae [Subfamily Fringillinae] [Subfamily Geospizinae] | Subf. Richmondeninae Subfamily Thraupinae Subfamily Fringillinae (including Emberizinae and Geospizinae) | Subfamily Pyrrhuloxiinae Subfamily Thraupinae [In Parulidae above] Subfamily Carduelinae |